metabolic acidosis in an afro-caribbean man with

SELF ASSESSMENT QUESTIONS

Metabolic acidosis in an Afro-Caribbean manwith hyperpigmentation

D A Darko, N N Chan, A Jackson, C Peiris, D O’Shea

A 46 year old Afro-Caribbean man presentedwith a 10 day history of increasing malaise,polydipsia, polyuria, and weight loss. One daybefore admission he had become increasinglyunwell and had repeated vomiting withoutabdominal pain. He regularly drank six units ofalcohol daily (42 units per week) and had con-sumed three pints of beer on the day of admis-sion. There was no previous history of diabetes,pancreatitis, or renal disease. His mother haddeveloped type 2 diabetes in her 30s, but noother family members were known to havediabetes or any endocrine diseases.

On examination, he was dehydrated, afebrile,mildly disorientated (Glasgow coma score14/15), and had no stigmata of chronic liverdisease. Kussmaul’s type respiration and ketoticbreath were evident. He was obese (body mass

index 35 kg/m2) with skin hyperpigmentation inthe distribution of the nape of his neck, axillae(fig 1), and extensor surfaces. He was tachy-cardic with a pulse rate of 100 beats/min, andhis blood pressure was 130/90 mm Hg onstanding and 110/80 mm Hg sitting. Abdomi-nal examination was unremarkable.

Biochemical investigations showed 3+ ke-tonuria on urine dipstick, arterial pH was 7.04,standard bicarbonate 4.0 mmol/l, carbon diox-ide tension 1.89 kPa, and oxygen tension 20.0kPa with a plasma glucose of 70 mmol/l. Serumsodium concentration was 134 mmol/l, potas-sium 3.6 mmol/l, urea 21 mmol/l, creatinine196 µmol/l, and calculated plasma osmolalitywas 374.6 mOsm/kg (normal range 278–305).His serum amylase was raised at 184 mU/l(normal range <100). Other investigationsincluding full blood count, liver function tests,a chest radiograph, and an electrocardiogramwere all normal. Septic screen including bloodand urine cultures were negative.

Questions(1) What is the metabolic condition in this

case? Discuss the possible diVerentialdiagnosis.

(2) What is the dermatological diagnosis (fig1) and which endocrine/metabolic condi-tions is this cutaneous sign associatedwith?

(3) What further investigations may be war-ranted in this patient?

Answers on p 439.

Figure 1 Hyperpigmentation in the axilla.

Postgrad Med J 2000;76:429–438 429

Department ofDiabetes andEndocrinology,Charing CrossHospital, FulhamPalace Road, LondonW6 8RF, UKD A DarkoN N ChanA JacksonC PeirisD O’Shea

Correspondence to:Dr Darko (e-mail:[email protected])

Submitted 18 February 1999Accepted 12 July 1999

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Swelling of a metacarpophalangeal joint

A Kumar, A P Thomas

A 60 year old man was referred to theorthopaedic clinic for swelling of the metacar-pophalangeal joint of the right middle fingerwhich had gradually increased in size over thelast five years. He was being treated with oralanti-inflammatory drugs for occasional dis-comfort. There was no history of fever, trauma,or involvement of any other joint. He had noother relevant medical history. On examinationthere was a slightly tender partly cystic swellingover the dorsoulnar aspect of the head of thethird metacarpal. There was a fixed flexiondeformity of 10 degrees at the metacar-pophalangeal joint but full flexion was possible.All the routine haematological and biochemicalinvestigations were normal. A radiograph of theright hand is shown in the fig 1.

Questions(1) What does the radiograph show?(2) What is the diVerential diagnosis?(3) How would you treat this condition?

A 30 year old male with headache and abnormalcranial magnetic resonance imaging

A S Kashyap, Shekhar Kashyap

A 30 year old male presented with history ofmild intermittent diVuse headache of fewweeks’ duration. There was no history of vom-iting, visual disturbances, diplopia, cranial sur-gery, or radiotherapy. On examination he wasof average built, with body mass index (weightin kg divided by height in m2) of 23. Clinicallyhe appeared tense and anxious. Blood pressurewas normal. Fundi and visual fields werenormal. There was no focal neurologicaldeficit. There were no clinical evidences of thy-roid, gonadotrophin, or glucocorticoid insuY-ciency. Other general and systemic examina-tions were normal. Cranial magnetic resonanceimaging (MRI) was done (fig 1).

Questions(1) What is the abnormality seen on MRI?(2) What are the two main types of this

abnormality?

Figure 1 Radiograph of right hand.

Answers on p 440.

Answers on p 441.

Figure 1 MRI of the brain.

430 Self assessment questions

Department ofTrauma andOrthopaedics, NewCross Hospital,Wolverhampton, UKA KumarA P Thomas

Correspondence to:Dr A Kumar, 99 Lea House,Bushey Fields Road, DudleyDY1 2LU, UK

Submitted 9 June 1999Accepted 5 July 1999

Department ofMedicine, ArmedForces MedicalCollege, Pune 411040,IndiaA S Kashyap

CardiothoracicCentre, GolibarMaidan, Pune, IndiaS Kashyap

Correspondence to:Dr A S Kashyap (e-mail:[email protected])

Submitted 19 April 1999Accepted 13 August 1999



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Sudden hemiplegia after a motorcycle accident

A M-H Ho, J D Wells

A 21 year old previously healthy man lost con-trol of his motorcycle and tumbled down to thebottom of an embankment. He suVered a briefloss of consciousness, got up, and, with pain inhis left arm, pushed the motorcycle up theembankment back onto the side of the road. Atthat point, he developed a sudden onset of dys-phasia and dense right hemiplegia.

At the hospital, he was found to have normalvital signs, a closed fracture of the left humerus,right hemiplegia with no other neurologicaldeficit, and normal computed tomography ofthe head. Digital subtraction left internal carotidarteriogram was immediately carried out.

Questions(1) What does the carotid arteriogram show

(figs 1 and 2)?(2) What is the best way to manage this

patient?(3) What is the diVerential diagnosis of acute

neurological deficit after trauma?

Answers on p 442.

Figure 1 Lateral view of the patient’s right internalcarotid arteriogram using digital subtraction techniquesshows a dissection.

Figure 2 Oblique view of the patient’s left internal carotidarteriogram shows a dissection.

Self assessment questions 431

Department ofAnaesthesia andIntensive Care, Princeof Wales Hospital, TheChinese University ofHong Kong Faculty ofMedicine, Hong KongA M-H Ho

Division ofNeurosurgery,Department ofSurgery, HamiltonHealth SciencesCorporation,McMaster UniversityFaculty of HealthSciences, Hamilton,Ontario, CanadaJ D Wells

Correspondence to:Dr Anthony Ho, Departmentof Anaesthesia and IntensiveCare, Prince of WalesHospital, Shatin, NT, HongKong (e-mail:[email protected])

Submitted 2 July 1999Accepted 13 August 1999



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A young man with acute paraparesis

H M S Elasha, D Footitt, J Gibson, T J Wilkin

A previously fit and well 32 year old man wasadmitted to the neurology ward in November1998 with a 24 hour history of rapidlyprogressive leg weakness such that he wasunable to stand. He felt tingling in his handsand lower legs, but no loss of sensation. Twoweeks earlier he had noticed intermittentweakness in both legs. He reported no otherneurological or constitutional symptoms.Twelve weeks earlier he had returned from aholiday in California.

His past medical history was unremarkableexcept for bronchial asthma controlled bysalbutamol and beclomethasone inhalers. Onfurther questioning, he admitted to unusuallymore colds than normal as well as mild fatigueand tiredness of six months’ duration.

On examination, he was tanned with palmarcrease and buccal pigmentation. His pulse wasregular at 80 beats/min, blood pressure was130/60 mm Hg (unable to stand to checkpostural drop), and his temperature was normal.The remaining general physical examinationwas normal. Higher mental function, cranialnerves, and speech were normal. His upper

limbs were stiV with a supinator catch butnormal power, sensation, and coordination. Thetone in his lower limbs was raised, with severepyramidal distribution weakness. All the deeptendon reflexes were very brisk with flexorplantars. Pinprick sensation was subjectivelydiminished in both feet with no sensory level.Other sensory modalities were intact. Magneticresonance imaging of the brain and spine werenormal. Routine investigations revealed a nor-mal full blood count, sodium concentration 116mmol/l, potassium 8.9 mmol/l (confirmed onrepeated sample), urea 17.2 mmol/l, creatinine165 mmol/l, glucose 5.8 mmol/l, bicarbonate 15mmol/l, chloride 86 mmol/l, and serum calciumwas normal. Thyroid function was normal. Anelectrocardiogram is shown in fig 1.

Questions(1) Describe the changes in the electrocardio-

gram(2) How would you explain the neurological

symptoms and signs?(3) What is the final diagnosis and how would

you confirm it?

Figure 1 Electrocardiogram of patient.

III

II

I

aVF

aVL

aVR

V3

V2

V1

V6

V5

V4

Answers on p 444.


Derriford Hospital,Plymouth, UK:Department ofEndocrinologyH M S ElashaT J Wilkin

Department ofNeurologyD FootittJ Gibson

Correspondence to:Dr H M S Elasha, MedicalDepartment, WestCumberland Hospital,Hensingham, Whitehaven,Cumbria CA28 8JG, UK(e-mail:[email protected])

Submitted 24 May 1999Accepted 18 August 1999



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Pain in the right wrist

S Shyamsundar, A L Pimpalnerkar

A 29 year old female typist presented with atwo year history of pain in her right wrist.There was no history of trauma nor was there ahistory of any other musculoskeletal disorder.Earlier radiographs (fig 1) and clinical exam-ination had proved inconclusive. Subsequentradiographs were taken eight and 12 monthslater (figs 2 and 3).

Questions(1) Describe the radiographic features in figs

1, 2, and 3.(2) What is the clinical diagnosis? What

investigation would have helped clinch thediagnosis at the first presentation.

(3) What would be your line of managementfor this patient? Rationalise your answer.

Answers on p 445.

Figure 1 Radiograph of the wrist taken previously.

Figure 2 Radiograph of the wrist taken eight months later.

Figure 3 Radiograph of the wrist taken 12 months later.


Department ofOrthopaedics, RoyalBournemouthHospital,Bournemouth, UKS ShyamsundarA L Pimpalnerkar

Correspondence to:Lt Cmdr A L Pimpalnerkar,Department ofOrthopaedics, Royal HospitalHaslar, Gosport, HantsPO12 2AA, UK

Submitted 18 June 1999Accepted 26 July 1999



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Atypical cellulitis

Debkumar Ray, Mitesh Khakhar, Alistair Flowerdew

A 76 year old man was admitted to the surgicalward with a two week history of right iliac fossapain associated with two days history of highfever (38.6°C) and right inguinoscrotal swell-ing. There were no associated bowel and/orurological symptoms. He was not diabetic andhad a coronary artery bypass graft in 1993. Onexamination he was slightly confused, dehy-drated, and pyrexial. Abdominal examinationrevealed an ill defined tender lump over rightlumbar area along with a tender right inguino-scrotal swelling. There was evidence of celluli-tis and spreading lymphangitis over the rightgroin.

A plain abdominal and chest x film werenormal. A full blood count showed a white cellcount of 10.6 × 109/l and haemoglobin concen-tration of 136 g/l. Blood urea concentrationwas 10.9 mmol/l and serum creatinine 86mmol/l. Computed tomography was per-formed next morning.

Two interesting sections of the scan areshown in figs 1 and 2.

Questions(1) What are the computed tomography find-

ings in figs 1 and 2?(2) What is the most likely diagnosis?(3) What should be the next step of manage-

ment?

Answers on p 446.

Figure 1 Computed tomogram of perineum and upper thigh.

Figure 2 Computed tomogram of lumbar area.


Department ofGeneral Surgery,Dorset CountyHospital, Dorchester,Dorset, UKD RayM KhakharA Flowerdew

Correspondence to:Mr D Ray, 32 Falconview,Badger Farm, WinchesterSO22 4EP, UK (e-mail:[email protected])

Submitted 21 May 1999Accepted 19 August 1999



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An interesting electrolyte problem

Ruxana T Sadikot, Ivan M Robbins

A 76 year old white man was admitted to theintensive care unit with a one day history ofconfusion, altered mental status, and a threeday history of nausea, vomiting, and abdominaldiscomfort. On the day of admission he wasinitially taken to a local hospital where anasogastric tube was placed and three litres ofblood tinged aspirate was obtained. Thepatient was transferred to our facility forfurther care. His past medical history wassignificant for hypertension, peptic ulcer dis-ease and long standing constipation for whichhe used 2–3 bottles per day of milk of magne-sia. His other prescribed medications includedamlodipine and vitamin supplements. Hedenied use of alcohol or illicit drugs. On exam-ination he was afebrile, his blood pressure was

106/52, and pulse rate 93 beats/min. He wasconfused and disorientated to time and place.His abdomen was soft to palpation withhypoactive bowel sounds. There were no focalneurological signs. The remainder of the physi-cal examination was unremarkable. His base-line and initial electrolytes are shown in table 1.Results of a liver function test and completeblood count were within normal limits.

Questions(1) What additional history would help in

making a diagnosis?(2) What is the most likely explanation for the

electrolyte disturbance?

Answers on p 447.

Table 1

Baseline (serum) Admission (serum) Post-treatment (serum) Urine electrolytes (on admission)

Sodium (mmol/l) 140 141 143 12Potassium (mmol/l) 4.2 3.0 4.0 22Chloride (mmol/l) 105 60 110 12Bicarbonate (mmol/l) 28 65 27 —Calcium (mmol/l) 23 3.6 2.1 —Magnesium (mmol/l) 0.9 2.6 0.9 —BUN (mmol/l of urea) 3.6 31.7 15.0 —Creatinine (µmol/l) 79.6 530.4 168.0 —pH — 7.46 7.42 —PCO2 (kPa) — 5.6 5.1 —

BUN = blood urea nitrogen; PCO2 = carbon dioxide tension.


Department ofMedicine, Division ofAllergy, Pulmonaryand Critical CareMedicine, VanderbiltUniversity School OfMedicine andDepartment ofVeterans AVairsMedical Center,Nashville, Tennessee,USAR T SadikotI M Robbins

Correspondence to:Dr Ruxana T Sadikot,Division of Allergy,Pulmonary and Critical CareMedicine, VanderbiltUniversity School ofMedicine, T-1217 MCN,Center for Lung Research,Nashville, TN 37232-2650,USA (e-mail:[email protected])

Submitted 20 July 1999Accepted 13 August 1999



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Respiratory compromise relieved by laparotomy

Anu Bali, David A Walker, John P Iredale, Colin D Johnson

A 40 year old woman presented with a fourmonth history of lethargy, reduced appetite,diarrhoea, and weight loss. In addition shecomplained of shortness of breath on exertion.Her alcohol intake was high with consumptionin excess of 28 units of alcohol per day. Eight-een months previously she had been investi-gated at another hospital for epigastric painand had been found to have a pancreatic pseu-docyst of 3 cm in diameter and she wasadvised to stop drinking alcohol. There was noother past medical history of note. Examina-tion at first presentation revealed the presenceof spider naevi with an enlarged liver, extend-ing some 7 cm below the costal margin, withmarked ascites, raised serum amylase and liverenzymes: alkaline phosphatase 362 IU/l,alanine aminotransferase 24 IU/l, amylase118 IU/l, and ã-glutamyltransferase 835 IU/l.The provisional clinical diagnosis made wasadvanced alcoholic liver disease with cirrhosis.An outpatient chest radiograph and abdomi-nal ultrasound were arranged and a follow upappointment made for one month.

After the ultrasound, urgent admission wasarranged. She had developed symptoms ofbreathlessness that were suYciently severe thatwalking to the bathroom precipitated dyspnoea.On examination she had a displaced cardiacapex beat, a third heart sound, reduced breathsounds at both lung bases, and a mass in theright upper quadrant of her abdomen. Herbiochemistry tests were repeated: alkalinephosphatase 464 IU/l; alanine aminotransferase12 IU/l, amylase 446 IU/l, and ã-glutamyl-transferase 186 IU/l. Chest radiographs atadmission are shown in figs 1A and B.

Questions(1) What does the chest radiograph show and

what would be your next investigation?(2) What is the diagnosis and how would you

manage this patient?

Answers on p 448.

Figure 1 Chest radiographs: anteroposterior (A) andlateral (B) views.


SouthamptonUniversity Hospital,Southampton, UKA BaliJ P Iredale

Intensive Care Unit,Queen AlexandraHospital, Portsmouth,UKD A Walker

UniversityDepartment ofSurgery, SouthamptonUniversity Hospital,Southampton, UKC D Johnson

Correspondence to:Dr J P Iredale, UniversityDepartment of Medicine,Mail point 811,Southampton UniversityHospital, Tremona Road,Southampton SO16 6YD,UK (e-mail:[email protected])

Submitted 6 July 1998Accepted 26 July 1999



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Chronic non-healing ulcers of the scalp aftertrauma

Vyjayanti Kulkarni, Vedantam Rajshekhar

A 11 year old boy presented with soft tissueswelling and multiple discharging sinuses overthe forehead, which he had had for past eightmonths. There was no history of tuberculosisor any major illness. There had been noresponse to antibiotic treatment. He hadsustained a forehead laceration in a road traYcaccident, four years ago, which was primarilysutured and had healed well. Systemic andneurological examinations were normal. Localexamination revealed a soft to firm, subcutan-eous swelling over the forehead with multiplesinuses, discharging serosanguinous andgranular material.

The biochemical tests were unremarkableexcept for a high erythrocyte sedimentationrate of 125 mm/hour. HIV testing was negative.Chest radiography showed no abnormality.The skull x ray film showed irregular patchyareas of radiolucencies in the right frontal andanterior parietal bones, with no surroundingsclerosis (figs 1 and 2). Cranial computed tom-ography revealed corresponding bone hy-podensities, with a thin layer of epiduralenhancement.

Questions(1) What is the diVerential diagnosis of this

clinical presentation and radiological pic-ture?

(2) How should this patient be managed?(3) What is the optimal treatment of this con-

dition?

Answers on p 450.

Figure 1 Plain radiograph of the skull, lateral view, showing multiple irregular patchyradiolucencies involving the frontal and parietal bones.

Figure 2 Plain radiograph of the skull, anteroposteriorview, showing multiple irregular patchy radiolucenciesinvolving frontal and parietal bones.


Department ofNeurological Sciences,Christian MedicalCollege Hospital,Vellore, India 632004V KulkarniV Rajshekhar

Correspondence to:Dr V Rajshekhar, CMCHospital, Vellore, 632004,India (e-mail:[email protected])

Submitted 19 April 1999Accepted 26 July 1999



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An unusual complication of carcinoma of thecaecum

Y Ramkissoon, H Ghoorahoo, S F Haydock, K M O’Shaughnessy

A 64 year old woman presented with loss ofappetite, weight loss, and altered bowel habit. Abarium enema confirmed the presence of acaecal carcinoma. A liver ultrasound scan wasnormal and admission for a right hemicolec-tomy was planned. Three days before theplanned admission, she awoke with severe painin the left gluteal region. Over the next fewhours the pain increased in severity and theaVected region became swollen and discol-oured. She was referred for hospital admission.On arrival at hospital she was apyrexial, with atachycardia of 120 beats/min but a blood pres-sure of 140/86 mm Hg. She was noted to havea large (>10 cm) well demarcated area of red-dish purple discoloration over her left thigh.Power and reflexes were reduced in the left leg.The area of the lesion spread rapidly and

crepitus developed. A surgical opinion wassought. An urgent computed tomogram wasrequested to determine the full extent of thelesion before surgical intervention. Imageswere obtained of the pelvic and gluteal region(fig 1) and the thorax (fig 2). The patientremained alert and comfortable during theimaging. Shortly after the scan was completed,however, the patient suVered a cardiac arrestwith electromechanical dissociation and died.

Questions(1) What abnormality is seen on the com-

puted tomogram in fig 1?(2) What is the lethal abnormality present on

the computed tomogram in fig 2?(3) What is the underlying diagnosis and

what are the treatment options for thiscondition?

Answers on p 451.

Figure 1 Computed tomogram of thigh region.

Figure 2 Computed tomogram of thorax.


Clinical PharmacologyUnit, Department ofMedicine,Addenbrooke’sHospital, Cambridge,UKY RamkissoonH GhoorahooS F HaydockK M O’Shaughnessy

Correspondence to:Dr K M O’Shaughnessy,Clinical Pharmacology Unit,Addenbrooke’s Centre forClinical Investigation, Box110, Addenbrooke’sHospital, Hills Road,Cambridge CB2 2QQ, UK(e-mail:[email protected])

Submitted 21 April 1999Accepted 19 August 1999



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SELF ASSESSMENT ANSWERS

Metabolic acidosis in an Afro-Caribbeanman with hyperpigmentation

Q1: What is the metabolic condition inthis case? Discuss the possible diVerentialdiagnosisThe presence of marked hyperglycaemia,ketonuria, and metabolic acidosis confirmedthe diagnosis of diabetic ketoacidosis. Otherpossible causes of anion gap metabolic acidosisin this case include alcoholic ketoacidosis,acute pancreatitis, and acute renal failure withuraemic acidosis.

Although alcohol may have contributed tothe development of ketoacidosis in this case, itis unlikely to the sole cause since plasmaglucose is often low or normal in alcoholicketoacidosis1 whereas it is markedly raised inthis case. The increased serum amylase raisesthe possibility of acute pancreatitis which maylead to lactic acidosis. However the patient didnot have abdominal pain throughout thecourse of his illness, and serial measurementsof the serum amylase showed further elevation.The mildly increased serum amylase was morelikely due to the renal impairment as amylase isrenally excreted. Finally, the uraemia in acuterenal failure may have contributed to the meta-bolic acidosis, although not to a great extent asthe renal function (peak plasma urea was 21mmol/l) of our patient improved almost imme-diately after treatment.

Q2: What is the dermatological diagnosis(fig 1, p 429) and which endocrine/meta-bolic conditions is this cutaneous signassociated with?The presence of velvety, rough, and hyperpig-mented skin in the distribution of the nape ofthe neck, axilla, and extensor surfaces isconsistent with the clinical diagnosis of acan-thosis nigricans. This cutaneous sign is associ-ated with many endocrine and metabolic con-ditions as listed in box 1.2 3

Q3: What further investigations may bewarranted in this patient?Further investigations should aim at excludingother causes of metabolic acidosis, screeningfor potential metabolic/endocrine pathologiesassociated with acanthosis nigricans, andpredicting future insulin requirement in thispatient.

In this patient endocrine investigations wereunremarkable including growth hormone, in-sulin like growth factor-1, androgen profile,overnight dexamethasone suppression test, and24 hour urinary free cortisol on two separateoccasions. He had autonomous insulin secre-tion as evidenced by a fasting serum C peptideof 1231 pmol/l and in addition negativeanti-islet cell and antiglutamic acid decarboxy-lase (GAD) antibodies.

Clinical courseThis patient made good progress after initia-tion of treatment with intravenous fluid, insulininfusion, and prophylactic broad spectrumantibiotics. His serum amylase, plasma urea,and creatinine returned to normal. A randomserum cholesterol was 4.3 mmol/l and triglyc-eride 2.86 mmol/l. He made an uncomplicatedrecovery and was discharged on HumanMixtard 30/70 36 units twice daily with dietaryadvice. After dietary modification, his homeglucose reading was excellent (4–6 mmol/l)which led to gradual reduction and finallywithdrawal of insulin. With diet control alone,his fasting glucose remained satisfactory at 6.4mmol/l and HbA1c of 5.9% when reviewednine months later despite no significant changein his weight.

DiscussionDiabetic ketoacidosisis is common in type 1diabetes, although it can also occur in type 2diabetes4 5 usually in the presence of metabolicstress or pancreatic â-cell failure. Rarely,diabetic ketoacidosisis can also occur in insulinresistant states such as acanthosis nigricans6

and acromegaly.7 The aetiology of diabeticketoacidosisis occurring in the presence of cir-culating insulin in these resistant states remainsunclear but may be related to severe underlyinginsulin resistance.

The recognition of underlying insulin resist-ance is important in the management of thesepatients. Conventionally, the occurrence ofdiabetic ketoacidosisis signifies the require-ment of lifelong insulin therapy. However, inindividuals with insulin resistance long terminsulin therapy may lead to weight gain, whichcould worsen the underlying insulin resistance.The clinical course of our patient wouldsuggest that the glucose intolerance in thisgroup of patients may be satisfactorily control-led with diet alone. The absence of anti-isletcell and GAD antibodies (an investigation notreadily available currently in secondary care)suggest that they are unlikely to be insulindependent in the future.8 Similar cases have

Box 1: Acanthosis nigricans:endocrine/metabolic associations2 3

x Obesity

x Insulin resistance

x Hyperinsulinaemia

x Type 2 diabetes mellitus

x Hypothyroidism

x Hypogonadism

x Hyperprolactinaemia

x Addison’s disease

x Cushing’s syndrome

x Acromegaly

x Polycystic ovary syndrome

x Pituitary tumours

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previously been described in a series ofAfrican-American type 2 diabetic patients(n=79), with negative anti-islet cell and GADantibodies who presented with hyperglycaemiawith or without ketoacidosis, and were insulinindependent at 3–12 months of initialpresentation.9 Near normoglycaemic remissionon dietary treatment alone, lasted a median of3.5 years and about 15% of their patients had aremission greater than five years.9 It is beenproposed that diVerences in â-cell glucose sen-sitivity and insulin secretion exist within ethnicpopulations, and the African-American type 2diabetic subjects may have a greater â-cellinsulin secretory defect.10 Close follow up ofthese patients and their insulin requirements isimportant to determine which diagnosticcategory, ketoacidosis onset type 2 diabetes orlate onset type 1 diabetes, they fall into.

Final diagnosisDiabetic ketoacidosis and acanthosis nigricans.

1 Fulop M. Alcoholic hypoglycaemia and ketosis. West J Med1979;131:321–2.

2 Matsuoka LY, Wortsman J, Gavin JR, et al. Spectrum ofendocrine abnormalities associated with acanthosis nigri-cans. Am J Med 1987;83:719–25.

3 Winkelmann RK, Randolph Scheen S, Underdahl LO.Acanthosis nigricans and endocrine disease. JAMA 1960;174:1145–52.

4 Bagg W, Sathu A, Streat S, et al. Diabetic ketoacidosis inadults at Auckland Hospital, 1988–1996. Aust N Z J Med1998;28:604–8.

5 Nagasaka S, Ishikawa SE, Itabashi N, et al. Ketoacidosis-onset type 2 diabetes in Japanese. Diabetes Care 1998;21:1376–7.

6 Bau CT, Sheu WHH, Song YM, et al. Acanthosis nigricansand diabetic ketoacidosis. Diabetes Care 1997;20:1202.

7 Katz JR, Edwards R, Khan M, et al. Acromegaly presentingwith diabetic ketoacidosis. Postgrad Med J 1996;72:682–3.

8 Littorin B, Sundkvist G, Hagopian W, et al. Islet cell andglutamic acid decarboxylase antibodies present at diagnosisof diabetes predict the need for insulin treatment. DiabetesCare 1999;22:409–12.

9 Banerji MA, Chaiken RL, Lebovitz HE. Long-term normo-glycemic remission in black newly diagnosed NIDDM sub-jects. Diabetes 1996;45:337–41.

10 Osei K, Gaillard T, Schuster DP. Pathogenetic mechanismof impaired glucose tolerance and type 2 diabetes inAfrican-Americans: the significance of insulin secretion,insulin sensitivity and glucose eVectiveness. Diabetes Care1997;20:396–404.

Swelling of a metacarpophalangeal joint

Q1: What does the radiograph show?Radiograph shows multiple rounded areas ofcalcification over the head of third metacarpaland erosion of the head of the metacarpal.

Q2: What is the diVerential diagnosis?The most likely diagnosis on the basis ofhistory, clinical examination, and radiographicappearance is synovial osteochondromatosis.The other possible diVerential diagnoses arelisted in box 1.

Q3: How would you treat this condition?Treatment usually involves removal of theosteocartilaginous nodules with excision of theinvolved synovium.

DiscussionSynovial chondromatosis is an uncommonpathological condition which mostly involvesthe synovium of a large joint and rarely occursin the hand. However a few cases aVectingsmall joints of the hand have been reported inthe literature.1–4 Pathologically it arises frommetaplasia of the synovium of the joint andrarely the tendon sheaths. It has been postu-lated that the multipotential synovioblastsunder unknown conditions undergo multifocalmetaplasia to form chondroblasts leading toformation of cartilaginous nodules. Thesenodules can later undergo secondaryossification.5 6

The clinical diagnosis of synovial chondro-matosis can be diYcult because of non-specificsigns and symptoms and rarity of the condi-tion. This disease should be considered in thediVerential diagnosis of a swollen and painfuljoint. The common presenting symptoms arepain, swelling, and stiVness of the joint. Physi-cal examination may show tenderness, eVu-sion, and palpable nodules. The radiographicappearance depends upon the extent of ossifi-cation of the cartilaginous nodules. In theabsence of such ossification the radiographmay show no abnormality and preoperativediagnosis may be diYcult. When the lesionoccurs with in the capsule of a small jointwhich has only limited capacity for expansion,secondary erosion of the bone can be seen. Inthis situation synovial chondrosarcoma shouldbe ruled out on histological examination.

Histological examination shows multiplecartilaginous masses beneath the synovium.These cartilaginous masses may separate fromthe synovium to form loose bodies. If the carti-laginous masses undergo ossification the con-dition is termed as synovial osteochondroma-tosis. The synovial origin of these cartilaginousmasses should be emphasised to diVerentiatethis condition from others. As histopathologyoften shows an increased cellularity and

Learning pointsx Acanthosis nigricans is commonly

associated with insulin resistance andtype 2 diabetes.

x Diabetic ketoacidosis, the hallmark oftype 1 diabetes, may also occur in type 2diabetes associated with insulin resistantstates.

x Normoglycaemic remission may occur inketoacidosis onset type 2 diabetes.

x Antibodies to islet cells and GADantibodies may serve as a useful guide topredict future insulin dependency.

Box 1: DiVerential diagnosesx Rheumatoid arthritis

x Chronic infection (includingtuberculosis)

x Trauma: osteochondral fracture

x Osteochondritis dissecans

x Osteoarthritis

x Neuropathic arthritis

x Gout

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nuclear atypia it is essential to avoid an errone-ous diagnosis of chondrosarcoma which re-quires a totally diVerent management.1 5

The natural history of the disease is of slowprogression and may be self limiting6 but ifuntreated for a long duration, it can lead to anextensive destruction of adjacent bonystructures.1 Malignant transformation, thoughreported,7 is uncommon. Although a case ofspontaneous regression of the disease involvingthe knee joint has been reported,8 the treat-ment usually involves removal of the cartilagi-nous nodules with en bloc excision of theinvolved synovium.

ProgressThe swelling was excised under general anaes-thesia. There was a loosely encapsulated massof immature cartilage arising from the dorsumof the metacarpophalangeal joint under theextensor hood. The histopathology was re-ported as synovial tissue together with frag-ments of varying sizes containing lobulatedhyaline chondroid tissue with no features ofmalignancy (fig 1 below). The patient remainsaymptomatic after three years of follow up.

Final diagnosisIntra-articular synovial osteochondromatosis.

1 Constant E, Harebottle NH, Davis DG. Synovial chondro-matosis of the hand. Plast Reconstr Surg 1974;54:353–8.

2 Cremone JC, WolV TW, Wolfort FG. Synovial chondroma-tosis of the hand. Plast Reconstr Surg 1982;69:871–4.

3 Takami H, Takahashi S, Ando M. Synovial chondromatosisof the proximal interphalangeal joint of a finger. J Hand Surg[Am] 1994;19:794–6.

4 Reed SC, Wright CS. Synovial chondromatosis of the meta-carpophalangeal joint: case report and review of theliterature. Can J Surg 1996;39:407–9.

5 Murphy FP, Dahlin DC, Sullivan CR. Articular synovialchondromatosis. J Bone Joint Surg Am 1962;44:77–86.

6 JeVreys TE. Synovial chondromatosis. J Bone Joint Surg Br1967;49:530–4.

7 Mullins F, Berard CW, Eisenberg SH. Chondrosarcoma fol-lowing synovial chondromatosis. Cancer 1965;18:1180–8.

8 Swan EF, Owens WF. Synovial chondrometaplasia: a casereport with spontaneous regression and a review of theliterature. South Med J 1972;65:1496–500.

A 30 year old male with headache andabnormal cranial magnetic resonanceimaging

Q1: What is the abnormality seen onmagnetic resonance imaging (see p 430)?Coronal contrast enhanced T1 weighted MRIscan through pituitary region demonstrates anenlarged sella turcica (C) with normallyenhancing pituitary tissue (I) displaced inferi-orly, an abnormality suggestive of empty sella.Optic chiasm (E), intracavernous carotidarteries (A: right and B: left side and sphenoidsinus (D, F) are clearly visible. This is often anincidental radiological finding and in mostcases there is no associated abnormality ofpituitary function. Pituitary fossa enlargementis a result of communicating extension of sub-arachnoid space (chiasmatic cistern) into thepituitary fossa. This promotes remodelling andenlargement of the bony sella. The pituitarygland is usually flattened against the floor of thesella, and the pituitary stalk may be deviatedlaterally.1

Q2: What are the two main types of thisabnormality?An empty sella can occur as a result ofcongenital diaphragmatic defect (primaryempty sella) or damage to the diaphragm bysurgery, radiation therapy, or pituitary tumourinfarction (secondary empty sella).

DiscussionA primary empty sella is a fairly common inci-dental radiological finding and is usually asso-ciated with only minor disturbances of pitui-tary function. In this condition the sella tendsto be symmetrically ballooned without bonyerosion. Suprasellar subarachnoid space (chi-asmatic cistern) herniates through an incom-plete diaphragma sella, so that the sella is filledwith cerebrospinal fluid (CSF) within anarachnoid lined sac. An incomplete dia-phragma sella appears to be a prerequisite.Whether persistently or transiently increasedCSF pressure is required to produce sellaenlargement in these patients is not clear. CSFpressure is generally normal, when measured,in these patients. Pituitary volume is usually

Figure 1 Photograph of the histology of the lesion showing lobulated hyaline chondroidtissue (haematoxylin and eosin; upper magnification × 20, lower magnification × 160).

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normal; this is in contrast with partially emptysella caused by a degenerated pituitary ad-enoma, where the pituitary volume is usuallyincreased.

Most patients with primary empty sella areobese, multiparous women with headaches;about 30% have hypertension.2 Selection biascannot be excluded in case reports, since skullradiographs may be obtained in patients withheadache, which in turn, uncovers the emptysella. Most patients with a primary empty sellahave normal pituitary function, and approxi-mately 15% have mild hyperprolactinaemia(usually <100 µg/l, with or without galactor-rhoea and amenorrhoea). Hyperprolactinae-mia may be due to stalk stretching orcoincidental microprolactinomas. Since even amild prolactin increase may result in gonadaldysfunction, this may merit treatment, butpatients should be reassured that this problemis usually unlikely to result in additional pitui-tary dysfunction. The development of pituitarydysfunction appears to be related to the degreeof sellar enlargement as demonstrated by com-puted tomography in 56 adults with normalpituitary function and 11 patients withhypopituitarism.3 Development of growth hor-mone secretory reserve is often abnormal inthese patients, probably as a result of obesity.Spontaneous CSF rhinorrhoea and pseudotu-mour cerebri have each been reported in 10%of these patients, but this association may rep-resent an ascertainment bias.2 CSF rhinor-rhoea may need surgical correction. Visual fielddefects have been reported and are thought tobe due to herniation of the optic chiasm intothe sella turcica. Once diagnosis of primaryempty sella syndrome is established on MRI orcomputed tomography, further diagnosticstudies should be performed to excludehormone excess or deficiency: when hormoneconcentrations are normal, therapy is reassur-ance.

Primary empty sella syndrome can alsooccur in children, with an incidence of 48% inchildren with either an isolated growth hor-mone deficiency or a combination of pituitaryhormone deficiencies; only 2% of children withnormal pituitary function have empty sella.3

Primary empty sella syndrome may be associ-ated with central precocious puberty.4 Associ-ation with midline defects and cleft palate hasbeen documented.5

In secondary empty sella associated withdestruction of pituitary gland, hypopituitarismis the outcome. Pituitary destruction occurswhen a large pituitary adenoma undergoes inf-arction (usually a haemorrhage) or as a conse-quence of surgical resection. Hypopituitarismmay be partial or complete, and measurementof serum pituitary and target organ hormonesis necessary to establish the diagnosis ofhormone deficiency and to determine the cen-tral (hypothalamic or pituitary) cause of thedysfunction.6

Follow upThis patient’s serum corticotrophin and corti-sol; thyrotrophin and thyroxine, luteinisinghormone and testosterone, and prolactin con-

centrations were normal. The patient refusedto undergo stimulation tests for growth hor-mone deficiency. He was reassured and treatedsymptomatically for his headache with goodresults. Cause of the headache is most likelytension, and is unrelated to primary empty sellasyndrome. He is on regular follow up in theendocrinology clinic.

Final diagnosisPrimary empty sella syndrome and tensionheadache.

1 Vance ML. Hypopituitarism. N Engl J Med 1994;330:1651–62.

2 Biller BMK, Daniels GH. Neuroendocrine regulation anddiseases of the anterior pituitary and hypothalamus. In:Fauci AS, Braunwald E, Isselbacher KJ, et al, eds. Harrison’sprinciples of internal medicine. New York: McGraw-Hill,1998: 1972–99.

3 Pocecco M, de Campo C, Marinoni S, et al. High frequencyof empty sella syndrome in children with growth hormonedeficiency. Helv Paediatr Acta 1988;43:295–301.

4 Rappaport R, Logrono R. Primary empty sella syndrome inchildhood: association with precocious puberty. Clin Pediatr(Phila) 1991;30:466–71.

5 Laron Z, Taube E, Kaplan I. Pituitary growth hormoneinsuYciency associated with cleft lip and palate: an embryo-nal developmental defect. Helv Paediatr Acta 1997;24:576–81.

6 Thorner MO, Vance ML, Laws ER Jr, et al. The anteriorpituitary. In: Wilson JD, Foster DW, Kronenberg HM, et al,eds. Williams textbook of endocrinology. Philadelphia: W BSaunders, 1998: 249–340.

Sudden hemiplegia after a motorcycleaccident

Q1: What does the carotid arteriogramshow?The digital subtraction arteriogram revealsdissection of the left internal carotid artery.The lateral (fig 1) and oblique (fig 2) views areshown (see p 431). The middle third of theinternal carotid artery shows marked narrow-ing giving it a rat-tail appearance (arrows).This extends to the petrous segment, beyondwhich the vessel is normal.

Q2: What is the best way to manage thispatient?The patient was immediately started onintravenous heparin therapy, with the targetactivated partial thromboplastin time set at2–2.5 times normal. His was admitted to theintensive care unit for monitoring and toensure hypotension and hypertension werepromptly controlled. His anticoagulation con-

Learning points

Primary empty sellax Common incidental radiological finding.

x Pituitary functions usually normal.

x Mild hyperprolactinaemia occurs in 15%of patients.

Secondary empty sellax Result of damage to diaphragma sella by

surgery or radiotherapy.

x Result of pituitary tumour infarction.

x Partial or complete hypopituitarism:common.




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tinued for six months with warfarin. Withphysiotherapy, his deficit largely resolved in theensuing six months.

Q3: What is the diVerential diagnosis ofacute neurological deficit after trauma?There are many ways for sorting out thevarious causes of acute neurological dysfunc-tion after trauma. The acronym HEADACHEmay help when timely diagnoses are needed(see box 1).

In this case, the patient likely suVered anacute embolic event, causing hypoperfusion.

DiscussionWhen stroke occurs in a young adult, one mustconsider cervicocerebral (carotid and verte-bral) artery dissection. The cause is usuallytraumatic: sports, instrumentation, penetrat-ing injuries, cervical manipulation, etc.However, even minor activities such as brush-ing teeth, coughing, and intercourse haveresulted in dissection.1 Post-traumatic dissec-tion involves a longitudinal intimal tearwith intramural bleeding. A large clot ob-structs the vascular lumen and can lead tothrombosis and distal embolism. Atheroscle-rosis and vascular pathology predispose to dis-sections.

The extracranial internal carotid artery is themost frequently reported site of cervicocer-ebral dissection.1 The vessel is tethered as itenters the foramen lacerum and can be injuredalong its entire relatively unprotected course.2

Carotid dissections sometimes result in cer-ebral ischaemia owing to haemodynamic com-promise from stenosis, but more often toembolism of thrombotic fragments.3 Disrup-tion of the endothelial surface exposes throm-bogenic elements to the blood.

The diagnosis of cervical carotid dissectionis based on clinical picture (head and neckpain, cerebral ischaemia, cranial nerve com-pression, and subarachnoid haemorrhage) andarteriographic findings.1 2 Normal brain com-puted tomography in an acutely hemiplegicperson who has had recent cervicocerebraltrauma (our patient had a concussion and lefthumeral fracture) should prompt the diagnosisof an arterial dissection.1 Stroke occurs in 56%of cases of blunt internal and common carotidtraumatic injury.4 The deficits, usually from anembolic event, occur after a lucid interval usu-ally of several hours to a few days after the

insult (∼1 hour in our case).2 Dissectionusually begins >2 cm distal to the carotidbifurcation and extends rostrally, terminatingbefore entry of the artery into the petrous bone(as was seen in this case), where mechanicalsupport limits further dissection. Irregularnarrowing of the artery is the most frequentarteriographic finding, resulting in a “wavyribbon” appearance, or a “string sign” ifsevere.2 A tapered occlusion beginning distalto the carotid sinus is less specific, but occursin about 20% of cases.2 Intimal flaps may beseen near the proximal margin of the dissec-tion. An extraluminal pouch (dissecting aneu-rysm) may be visualised distally, usually nearthe base of the skull.2

The acute prognosis of patients who havearterial dissections not complicated by strokesis good.1 The acute prognosis of ischaemicstroke is less favourable and reflects the extentof the infarction and is not specific to thearterial process.1 Bogousslavsky et al wrotethat of 30 patients with strokes secondary todissections, seven died, and 12 made goodrecoveries.5 Patients with intracranial dissec-tions have a poorer prognosis than thosewith extracranial lesions, in part becausethe dissections may be complicated by sub-arachnoid haemorrhage.1 The danger of earlyand late recurrent stroke is not high for thosewithout severe underlying atherosclerosis orvascular pathology. Overall, regression orresolution of the stenotic arterial lesion is therule.

Since most cerebral injury probably resultsfrom thromboembolic complications of thedissection,3 patients with acute ischaemicevents and without subarachnoid haemorrhage(as in extracranial carotid dissection) are givenintravenous heparin, followed by oral antico-agulants. Therapy is continued until repeatvessel imaging at three months, and beyond ifnecessary, shows good resolution.2 Long term

Box 1: HEADACHEx Haematoma

x Elevated intracranial pressure

x Air or fat embolism

x DiVuse axonal injury

x Alcohol and drugs, metabolic causes(diabetes, thyroid, etc)

x Cord injury

x Hypoperfusion and hypoxia

x Epilepsy

Learning pointsx Cervicocranial arterial dissections

can result from even minor trauma; itis an uncommon cause of acuteischaemic stroke, except among youngadults.

x Extracranial carotid dissection is thecommonest type of cervicocranialdissection.

x Normal computed tomography ofthe brain in an acutely hemiplegicperson after trauma should raise thepossibility of cervicocranial arterialdissection.

x In the absence of haemorrhage, mostcarotid dissections with ischaemia can betreated with 3–6 months ofanticoagulants; antiplatelet therapy isgiven in dissection with no ischaemia.

x Long term prognosis tends to befavourable in dissections withoutsubarachnoid haemorrhage.




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antiplatelet therapy may be needed for thosewith persistent lumen irregularities. Patientswithout ischaemic symptoms may be givenantiplatelet therapy for 6–12 months from theoutset. Surgical intervention may be contem-plated in select cases.

Final diagnosisTraumatic dissection of the extracranial inter-nal carotid artery.

1 Adams Jr HP, Love BB, Jacoby MR. Arterial dissections. In:Ginsberg MD, Bogousslavsky J, ed. Cerebrovascular disease:pathophysiology, diagnosis, and management. Malden, MA:Blackwell Science 1998: 1430–46.

2 Saver JL, Easton JD. Dissections and trauma of cervico-cerebral arteries. In: Barnett HJM, Mohr JP, Stein BM,Yatsu FM, ed. Stroke: pathophysiology, diagnosis, andmanagement. 3rd Ed. New York: Churchill Livingstone,1998: 769–86.

3 Steinke W, Schwartz A, Hennerici M. topography ofcerebral infarction associated with carotid artery dissection.J Neurol 1996;243:323–8.

4 Ramadan F, Rutledge R, Oller D, et al. Carotid arterytrauma: a review of contemporary trauma center experi-ences. J Vasc Surg 1995;21:46–55.

5 Bogousslavsky J, Despland P-A, Regli F. Spontaneouscarotid dissection with acute stroke. Arch Neurol 1987;44:137–40.

A young man with acute paraparesis

Q1: Describe the changes in theelectrocardiogramThe electrocardiogram shows small P waves,broad QRS complexes, and peaked T waves, allof which are consistent with hyperkalaemia.Other electrocardiographic features of hyper-kalaemia include prolongation of the PR inter-val, complete heart block, and atrial asystole.Ventricular fibrillation and standstill may occurwith severe hyperkalaemia.

Q2: How would you explain theneurological symptoms and signs?The acute paraparesis is due to hyperkalaemicparalysis. The patient was treated with intra-venous calcium gluconate, sodium bicarbo-nate, and dextrose and insulin infusion. Hemade a quick symptomatic recovery withinone hour after starting treatment. Hyperkalae-mic paralysis which may mimic the picture ofacute Guillain-Barré syndrome has beenpreviously described.1 Hereditary hyperkalae-mic paralysis is a separate clinical entity.Causes of secondary hyperkalaemic paralysisis shown in box 1.

Q3: What is the final diagnosis and howwould you confirm it?All the biochemical abnormalities are second-ary to chronic autoimmune primary adrenal

insuYciency (Addison’s disease). The shortSynacthen (tetracosactrin) stimulation test, isthe most commonly used test for the diagnosisof primary adrenal insuYciency. Adrenal func-tion is considered to be normal if the basal orpostcorticotrophin (Synacthen) plasma corti-sol is at least 500 nmol/l or preferably, at least550 nmol/l.2 Basal plasma adrenocortico-trophic hormone concentration is usuallyraised in primary adrenal insuYciency. Thispatient showed a flat cortisol response afteradministration of Synacthen (cortisol concen-tration 107, 105, and 122 nmol/l at 0, 30, and60 mins respectively). His antiadrenal cortexantibodies were strongly positive. He wastreated with intravenous fluids, hydrocorti-sone, and fludrocortisone. He was well, and hiselectrolytes and renal function were normalwhen seen as an outpatient two weeks later.Causes of primary adrenal insuYciency areshown on box 2.3

DiscussionThe symptoms and signs of chronic primaryadrenal insuYciency are non-specific and mayvary depending on the chronicity and severityof the adrenal destructive process, and therelative deficiency of glucocorticoids andmineralocorticoids. Patients can present withfatigue, weakness, listlessness, orthostatic hy-potension, and weight loss. Gastrointestinalsymptoms such as abdominal cramps, nausea,anorexia, vomiting, and diarrhoea are oftenthe presenting features. Hyperpigmentationwhich aVects the skin and mucosal surfaces isthe most specific sign of chronic primary adre-nal insuYciency, but its absence does notexclude this diagnosis. Addison’s disease my

Box 1: Causes of hyperkalaemicparalysisx Renal failure.

x Adrenal insuYciency.

x Rhabdomyolysis.

x Administration of potassium salts inintravenous infusions.

x Aldosterone antagonist (spiranolactone).

Box 2: Causes of primary adrenalinsuYciency

Gradual onsetx Autoimmune adrenalitis.

x Tuberculosis.

x Adrenomyeloneuropathy.

x Systemic fungal infections (for example,histoplasmosis).

x AIDS (opportunistic infections withviruses, fungi, bacteria, or protozoa).

x Metastatic carcinoma (bronchial, breast,lymphoma).

x Adrenal infiltration (amyloidosis,sarcoidosis, haemochromatosis).

x Drugs (ketoconazole,aminoglutethimide, suramin, mitotane,metyrapone).

Acute onsetx Meningococcal and other septicaemias.

x Warfarin therapy.

x Coagulation disorders.

x Antiphospholipid syndrome.

x Abdominal trauma.




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be misdiagnosed as anorexia nervosa4 ordepression.5

Acute adrenal insuYciency is a life threaten-ing medical emergency which needs immediatemedical action. Once the diagnosis is sus-pected, treatment should be instituted and notdelayed for investigations. Plasma samples canbe saved for later analysis of the cortisolconcentration to confirm the diagnosis. Hypo-tension, nausea, vomiting, and diarrhoea areprominent features.

In the early stages of chronic adrenal failure,the serum electrolytes are normal, but abnor-malities such as hyponatraemia, hyperkalae-mia, metabolic acidosis, and renal impairmentoccur in the later stages of the disease whenadrenal destruction is advanced. The hypo-natraemia is due to aldosterone deficiency andvasopressin secretion secondary to hypovolae-mia. Hyperkalaemia is due to a combination ofaldosterone deficiency, acidosis, and renalimpairment.

Our patient presented with the acute neuro-muscular manifestations of hyperkalaemia (hy-perkalaemic paralysis) in the absence of theclassical symptoms of chronic adrenal failure,which is a very unusual presentation ofAddison’s disease.

The predominance of hyperkalaemia in thispatient could be partly explained by theabsence of vomiting and diarrhoea, which tendto lower the serum potassium level. In additionthe severity of metabolic acidosis in thepresence of renal impairment is an othercontributing factor.

The management of primary adrenal insuY-ciency consists of glucocorticoid and mineralo-corticoid replacement, usually in the form ofhydrocortisone and fludrocortisone respec-tively. Patients should carry a card containinginformation on current therapy, and theyshould also wear a bracelet or necklace, such asthose issued by Medic Alert.6

Patients must also be advised to double upthe dose of hydrocortisone for a few days if theydevelop a febrile illness, and they should keepampoules of hydrocortisone in the fridge athome for intramuscular injection, or hydrocor-tisone suppositories to be used in case ofvomiting.7

This case emphasises the importance ofexcluding metabolic abnormalities in patientspresenting with acute neurological symptomsas the response to treatment is usually prompt,and the outcome rewarding.

Final diagnosisHyperkalaemic paralysis secondary to chronicautoimmune primary adrenal insuYciency(Addison’s disease).

1 Naumann M, Reiners K, Schalke B, et al. Hperkalaemiamimicking acute Guillain-Barré syndrome. J Neurol Neuro-surg Psychiatry 1994;57:1436–7.

2 May ME, Vaughn ED, Carey RM. AdrenocorticalinsuYciency—clinical aspects. In: Vaughn ED Jr, CareyRM, eds. Adrenal disorders. New York: Thieme Medical,1989: 171–89.

3 Oelkers W. Adrenal insuYciency. N Engl J Med 1996;335:1206–12.

4 Tobin MV, Morris AI. Addison’s disease presenting asanorexia nervosa in a young man. Postgrad Med J 1988;64:953–5.

5 Keljo DJ, Squires RH. Just in time. N Engl J Med 1996;334:46–8.

6 Werbel SS, Ober KP. Acute adrenal insuYciency. EndocrinolMetab Clin North Am 1993;22:303–28.

7 Newrick PG, Braatvedt G, Hancock J, et al. Self-management of adrenal insuYciency by rectal hydrocorti-sone. Lancet 1990;335:212–3.

Pain in the right wrist

Q1: Describe the radiographic features infigs 1, 2, and 3 (see p 433)The radiographs of the right wrist showprogressive sclerosis and fragmentation of thelunate bone.

Q2: What is the clinical diagnosis? Whatinvestigation would have helped clinchthe diagnosis at the first presentationThe radiographic progression is classical ofidiopathic avascular necrosis of the lunate:Kienböck’s disease. A bone scan or magneticresonance imaging at the first presentationwould have been valuable in clinching thediagnosis.

Q3: What would be your line ofmanagement for this patient? Rationaliseyour answerAs collapse of the lunate has occurred, surgicalprocedures are ineVective in realigning theulna. Management at this stage usually involvesreplacement of the lunate with a titaniumimplant1 or arthrodesis of the wrist.

DiscussionKienböck’s disease occurs typically in youngadults. Recognised predisposing factors in-clude local trauma and a relatively shortenedulna (negative ulnar variance). The latterpredisposes the lunate compression to againstthe distal radius.2 The patient classicallycomplains of pain and weakness of the aVectedwrist. Examination usually reveals a localisedarea of tenderness corresponding to the lunateand a significant reduction in grip strength. Inlater stages of the disease, wrist movements aremarkedly reduced. Based on the clinical andradiographic features four stages of the diseasehave been identified (see table 1).

Figure 1 Radiograph showing titanium implant.




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Final diagnosisAdvanced Kienböck’s disease of the rightlunate.

1 Swanson DH, Pierce TD. Carpal bone titanium implantarthroplasty. Clin Orthop 1997;342:46–58.

2 Gelberman RH, Salamon PB, Jurst JM, et al. Ulnar variancein Kienböck’s disease. J Bone Joint Surg Am 1975;57:674–6.

3 Weiss APC, Welland AJ, Moore JR, et al. Radial shorteningfor Kienböck’s disease. J Bone Joint Surg Am 1991;73:384–91.

Atypical cellulitis

Q1: What are the computed tomographyfindings in figs 1 and 2? (see p 434)Figure 1 is a section through the perineum andupper thigh showing a right vaginal hydrocoelewith normal testis.

Figure 2 is a section through the lumbar areashowing retroperitoneal gas, fluid, and necrotictissue displacing the right kidney anteriorly butboth kidneys look normal.

Q2: What is the most likely diagnosis?Right sided retroperitoneal abscess/necrotisinginfection, which is extending into right groinwith secondary hydrocoele.

Q3: What should be the next step ofmanagement?The patient should be rehydrated and shouldreceive intravenous high dose combinationantibiotics to start with and then should betaken to theatre for radical surgical debride-ment and drainage of pus/necrotic tissue.Finally further investigations are required toidentify the source of infection.

DiscussionWe treated this patient initially with high dosebroad spectrum antibiotics and intravenousfluid therapy with a provisional diagnosis ofpyonephrosis and right epididymo-orchitis.The plain x ray film of the abdomen was unre-markable and there was no evidence of anyrenal stones. The next morning computedtomography (with intravenous contrast but nooral contrast) revealed retroperitoneal necro-tising infection but without any definitesource. The patient was taken to theatre andunderwent a right orchidectomy along withdebridement of retroperitoneal necrotic tissueextraperitoneally via a separate lumbar inci-sion. During operation we found morenecrotic tissue and milky fluid rather thanfrank pus. Urgent Gram stain showed thepresence of Gram positive cocci and bacilli.He was started on high dose benzylpenicillin,metronidazole, and flucloxacillin along withparenteral feeding. Subsequent intravenousurography was normal but a barium enema(fig 1, right) revealed a polypoidal growth in

the caecum. Laparotomy and right hemicolec-tomy was performed for a locally invasiveadenocarcinoma of caecum with small intra-peritoneal tumour deposits. Eventually he wasdischarged home after two months of hospitalstay.

In summary, this man had retroperitonealnecrotising fasciitis (RNF) due to locally per-forated carcinoma of the caecum. RNF is arare variety of synergistic soft tissue infectionof retroperitoneum. Bowel perforation (carci-noma, perforated diverticular disease, or undi-agnosed strangulated hernia) and urinaryextravasation are commonly found as predis-posing pathology. RNF is very diYcult todiagnose in its early stage. A Medline searchhas revealed only three published articles onRNF.1–3 Almost all of the patients presentedwith abdominal wall, groin, and/or inner thighcellulitis with or without cutaneous gangrene.All of their patients were very ill systemicallywith severe pain being a key diagnostic symp-tom. Computed tomography has been foundto be a very useful diagnostic tool and if anybowel lesion is not evident on computed tom-ography, patients should have a barium enemaor colonoscopy. When in doubt, aspiration oftissue fluid and urgent Gram stain can be veryuseful. Frozen section biopsy of the necroticarea has been found to be of good value forearly diagnosis.4 Bacteriology usually revealsmixed growth of aerobic and anaerobic organ-isms, of which commonly found organisms are

Table 1 Four stages of Kienböck’s disease

Stage Features Management

Stage 1 Ischaemia without radiographic changes (fig 1, see questions) Rest, splintage, and analgesiaStage 2 Sclerosis of lunate (fig 2, see questions) Shortening of radius or lengthening of ulna3

Stage 3 Collapse of lunate (fig 3, see questions) Titanium implant (see fig 1, p 445) or radiocarpal fusionStage 4 Osteoarthritis of radiocarpal joint Wrist arthrodesis

Figure 1 Barium enema showing polypoidal growth in thecaecum.




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Streptococcus faecalis, S milleri, coliforms, andbacteroides spp. Prompt and radical surgicaldebridement of retroperitoneal tissue is thekey treatment and quite often repeat debride-ment is required.2 High dose combinationantibiotics are life saving. Hyperbaric oxygenhas been found to reduce the mortality andneed for repeat debridement,5 6 but its role isstill controversial.

Mortality is very high (range 37%–80%)depending on the extent of infection. Thegreat majority of patients, who had laparotomyto deal with bowel pathology and retroperito-neal necrosis at the same time, died in the earlypostoperative period because of septicaemiaand subsequent multiorgan failure.1 Ourpatient went home and is still alive and well sixmonths after surgery. We believe this isbecause in first stage we debrided retroperito-neal tissue extraperitoneally and subsequentlywe dealt with the primary pathology intraperi-toneally.

Final diagnosisRetroperitoneal necrotising fasciitis due tolocally perforated carcinoma of the caecum.

1 Woodburn KR, Ramsay G, Gillespie G, et al. Retroperito-neal necrotising fasciitis. Br J Surg 1992;79:342–4.

2 Mokoena T, Luvuno FM, Marivate M, et al. Surgical man-agement of retroperitoneal necrotising fasciitis by plannedrepeat laparotomy and debridement. S Afr J Surg 1993;31:65–70.

3 Ward RG, Walsh MS. Necrotizing fasciitis: 10 years’experience in a district general hospital. Br J Surg 1991;78:488–9.

4 Stamenkovic I, Daniel Lew P. Early recognition ofpotentially fatal necrotizing fasciitis, the use of frozen-section biopsy. N Engl J Med 1984;310:1689–93.

5 Riseman JA, Zamboni WA, Curtis A, et al. Hyperbaricoxygen therapy for necrotizing fasciitis reduces mortalityand the need for debridements. Surgery 1990;108:847–50.

6 Anonymous. Hyperbaric oxygen, more indications thanmany doctors realise (editorial). BMJ 1993;307:515–16.

An interesting electrolyte problem

Q1: What additional history would help inmaking a diagnosis?History of ingestion of antacids. The patientgave a history of using at least half to one bot-tle of antacids and several tablets of “Tums”(calcium carbonate) a day for heartburn andindigestion.

Q2: What is the most likely explanationfor the electrolyte disturbance?The triad of hypercalcaemia, alkalosis, andrenal failure suggests a diagnosis of milk alkalisyndrome with excessive ingestion of milk ofmagnesia. The alkalosis was aggravated byvomiting and nasogastric suction leading tovolume contraction.

Hospital courseAn abdominal film was obtained and intestinalobstruction was excluded. The patient wastreated with normal saline and other supportivemeasures. His electrolytes and renal functionnormalised within the next 24 hours (table 1).

DiscussionThe patient described above presented with asevere metabolic alkalosis (bicarbonate of 65mmol/l) and hypermagnesaemia. The patho-genesis of metabolic alkalosis in this case iscomplex and multifactorial. The triad ofhypercalcaemia, alkalosis, and renal failuresuggests a diagnosis of milk alkali syndrome.However, this syndrome is generally associatedwith hypokalaemia and hypomagnesaemia. Inthe patient presented here, excessive ingestionof milk of magnesia (Mg(OH)2) in the presenceof renal failure led to reduced excretion ofmagnesium thus causing hypermagnesaemia.The alkalosis was further aggravated by vomit-ing, nasogastric aspiration, and volume con-traction. Dehydration led to further deteriora-tion in renal function.

Alkalosis of this severity has only beenreported sporadically.1 2 Voyce et al reported acase of severe alkalaemia with a pH of 7.81, asa result of combined metabolic and respiratoryalkalosis.3 A serum bicarbonate concentrationof 96 mmol/l has been reported in a patient dueto excessive ingestion of sodium bicarbonate.2

Severe alkalaemia may be fatal and a mortalityas high as 41% has been reported with severemetabolic alkalosis.4

Metabolic alkalosis is categorised as salineresponsive if the urine chloride concentration isless than 15 mmol/l or saline resistant if theurine chloride is greater than 25 mmol/l.Volume depletion, either from gastrointestinallosses, diuretics, or renal compensation forhypercapnia are among the most commoncauses of chloride responsive metabolic alkalo-sis. Chloride resistant metabolic alkalosisresults from mineralocorticoid excess or potas-sium depletion. Evaluation of patients withmetabolic alkalosis includes assessment ofextracellular fluid volume, and urinary electro-lytes which helps to determine if the alkalosis ischloride responsive. Fluid repletion is themainstay of treatment of chloride responsivemetabolic alkalosis. In cases of very severealkalosis infusion of dilute hydrochloric acid(0.01N) may be required. The management ofchloride resistant alkalosis requires treatmentof the underlying cause.5

Hypermagnesaemia occurs rarely, and isusually iatrogenic.6 Elderly patients with renalfailure are at increased risk of developinghypermagnesaemia. Clinical manifestations ofhypermagnesaemia include vomiting, altered

Learning pointsx Retroperitoneal necrotising fasciitis

(RNF) is a rare but fatal condition.

x Any atypical cellulitis of the abdominalwall, groin, and inner thigh should betreated suspiciously.

x If in doubt computed tomography is avery good tool to diagnose RNF.

x Early and radical surgical debridement isessential with a view to redebridement.

x If RNF is diagnosed, a bowel lesionshould be sought for.




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mental status, and respiratory depression. Dis-continuation of magnesium is suYcient to cor-rect the problem in most cases, however,haemodialysis may be required to treat severecases.6

This case describes a complex and poten-tially fatal electrolyte and acid-base disorder,resulting from available and commonly usednon-prescription medication. History remainsan invaluable guide to the diagnosis of suchcomplex problems. Elderly patients should beparticularly warned against abuse of laxativesand antacids.

Final diagnosisMetabolic acidosis secondary to milk alkalisyndrome and nasogastric aspiration with milkof magnesia overdose.This work was supported by NIH Grant HL-07123.

1 Amundson DE, Diamant J. Severe metabolic alkalosis. SouthMed J 1994;87:275–7.

2 Rama B, Varghese J, Genova G, et al. Severe acute metabolicalkalosis. Nebr Med J 1993;78:151–4.

3 Voyce SJ, Goldfine HL, Gore JM. Severe metabolic and res-piratory alkalosis associated with the treatment of congestiveheart failure. Arch Intern Med 1987;147:2211–12.

4 Brimioulle S, Katn RJ. EVects of metabolic alkalosis on pul-monary gas exchange. Am Rev Respir Dis 1990;141:1185–9.

5 Gluck SL. Acid-base (review). Lancet 1998;352:474–9.6 Weisinger JR, Bellorin-Font E. Magnesium and phosphorus.

Lancet 1998;352:391–6.

Respiratory compromise relieved bylaparotomy

Q1: What does the chest radiograph showand what would be your nextinvestigation?The chest radiograph (see p 436) shows anabnormal cardiac shadow, which gives theappearance of a dextrocardia. Closer examina-tion, shows a mass on the right side, whichrepresents the right atrium being compressedforward by a posterior lesion. There is also adouble left cardiac border, the medial borderbeing the true one. The lateral borderrepresents a posterior mediastinal cyst. Bilat-eral pleural eVusions are also noted, moremarked on the right, and so the diVerentialdiagnosis should also cover other causes ofbilateral pleural eVusions. These includehypoproteinaemia secondary to nephrotic syn-drome or chronic liver disease and in addition,given that there are absent breast shadows, ina women of this age a possible diagnosis ofmetastatic breast carcinoma with previousmastectomies should also be considered. As anext investigation, contrast enhanced com-puted tomography of the abdomen would oVeruseful diagnostic information see figs 1 and 2(below).

Figure 1 Contrast enhanced computed tomography of the thorax demonstrating a large fluid containing mass in theposterior mediastinum compressing the heart and deviating it to the right. The scan also identifies bilateral pleural eVusionsand basal consolidation in the right lower lobe.




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Q2: What is the diagnosis and how wouldyou manage this patient?The diagnosis is mediastinal pancreatic pseu-docyst.

The images in figs 1 and 2 (above) show alarge pancreatic pseudocyst communicatingwith the posterior mediastinum via an exten-sion through the oesophageal hiatus of the dia-phragm.

The patient was then referred to a pancreaticsurgeon and the diagnosis was confirmed atlaparotomy. The mediastinal cyst was drainedby a tube passing through the diaphragm,across the abdominal cavity to the exterior, andthe abdominal pseudocyst was drained by cystgastrostomy.

Discussion of further managementMediastinal pseudocyst is a rare complicationof pancreatitis, with fewer than 60 casesreported in the English language.1 The pseudo-cyst is inflammatory in origin and the lesionlacks a true epithelial lining. As a consequence,extrapancreatic fluid collections, rich in pro-teolytic enzymes, fat, and necrotic debris accu-mulate outside the boundary of the gland sur-rounded by a thick fibrous capsule. Whilespontaneous resolution of pseudocysts hasbeen reported,2 this is unlikely if there isevidence of chronic pancreatitis, pancreaticduct abnormalities exist, or if ultrasound imag-ing suggests a thick walled lesion.3

The pathogenesis and natural history ofpseudocysts in acute and chronic pancreatitisare diVerent.4 Both lesions may lead toextension of the pseudocyst along fascial planeswhich oVer least resistance and may result inmediastinal pseudocyst formation. Entry to thethorax is most commonly seen via the oesopha-geal hiatus, aortic hiatus, or by direct erosionthrough the diaphragm.5

The review of mediastinal pseudocyst casereports by Beauchamp et al suggests that theyare more commonly seen in men, have amedian age of distribution of 45 years and mostcommonly present with dyspnoea, chest andabdominal pain, and weight loss. Dysphagiamay be present if there is oesophageal displace-ment by the extending pseudocyst. Recurrenthospital admissions for alcohol associated pan-creatitis was a feature in most reported cases.

Radiography findings and the role ofradiographyRadiographically non-specific findings of pleu-ral eVusion, pulmonary oedema, atelectasis,and cardiac enlargement may be accompaniedby more specific findings of mediastinalinflammation or abscess and mediastinalpseudocyst.6–8 Kirchner identified that whenpresent, pleural eVusions were most commonlyleft sided and the location of the thoracic masswas in the posterior mediastinum. Magneticresonance imaging and endoscopic retrograde

Figure 2 Contrast enhanced abdominal computed tomography demonstrating a large retroperitoneal fluid collection whichwas seen to be continuous with the intrathoracic collection on the complete series of the images obtained.




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cholangiopancreatography have proved usefulin diagnosis and planning treatment strategies.

Surgical optionsExternal drainage of the mediastinal pseudo-cyst represents the simplest surgical approachbut is associated with the highest mortality andgreatest recurrence rate.9 10 Erb and Grimeshighlight a greater recurrence of mediastinalpseudocyst with external drainage when com-pared with intra-abdominal drainage. Thus,while the thoracic symptoms often give thegreatest concern, mediastinal pseudocysts arebest managed by laparotomy rather thanthoracotomy. Thoracic drainage may be usefulpreoperatively if the cyst is infected. Theformation of a controlled fistula into thegastrointestinal tract by cyst intestinal anasto-mosis, represents the treatment of choice fornon-complicated mature pseudocysts and isassociated with lowest mortality and recur-rence rates. Internal decompression of thepseudocyst may be either with cyst gastrostomyor more commonly with cystojejunostomyRoux on Y.

ConclusionThis case highlights a rare complication ofpancreatic disease, manifesting with symptomsoutside the gastrointestinal tract. Mediastinalpseudocyst should be considered in the diVer-ential diagnosis when a patient with previouspancreatic disease presents with shortness ofbreath and unexplained thoracic radiographicfindings. Radiological techniques oVer invalu-able diagnostic information and may have arole in treatment. Currently, surgical interven-tion with internal abdominal drainage of thelesion close to the pancreas, and externaltransdiaphragmatic drainage of the intratho-racic component oVers the best therapeuticoutcome.

Final diagnosisMediastinal pancreatic pseudocyst.

The authors thank Dr Simon Jackson, Consultant Radiologist,at Derriford Hospital, Plymouth.

1 Edwards RD, Jardine A, Vallance R. Pancreaticpseudocyst—an unusual cause of palpitations. Clin Radiol1992;45:128–40.

2 Leechawengwong M, Berger HW, Romeu J. Spontaneousresolution of mediastinal pancreatic pseudocyst. Chest1979;75:632–3.

3 Warshaw AL, Rattner DW. Timing of surgical drainage forpancreatic pseudocyst. Ann Surg 1985;202:720–4.

4 Grace PA, Williamson RCN. Modern management of pan-creatic pseudocysts. Br J Surg 1993;80:573–80.

5 Beauchamp RD, Winsett M, Nealon WH. Operativestrategies in the management of mediastinal pancreaticpseudocyst. Surgery 1989;105:567–70.

6 Fishbein R, Murphy GP, Wilder RJ. The pleuropulmonarymanifestations of pancreatitis. Diseases of the Chest 1962;41:392–7.

7 Kaye MD. Pleuropulmonary complications of pancreatitis.Thorax 1969;23:297–306.

8 Roseman DM, Kowlessar OD, Sleisenger MH. Pulmonarymanifestations of pancreatitis. N Engl J Med 1960;263:294–6.

9 Bradley EL. Cysts and pseudocysts of the pancreas. Surgicalaspects. In: Berk JE, ed. Gastroenterology. Vol 6. London: WB Saunders, 1985: 4151–7.

10 Erb WH, Grimes EL. Pseudocysts of the pancreas: a reportof 17 cases. Am J Surg 1960;100:30.

Chronic non-healing ulcers of the scalpafter trauma

Q1: What is the diVerential diagnosis ofthis clinical presentation and radiologicalpicture?A chronic infection of skull and scalp was diag-nosed and pyogenic, tuberculous, and fungalosteomyelitis were considered in the diVeren-tial diagnosis.

Q2: How should this patient be managed?Chronic non-healing scalp infection needsthorough debridement of the wound and exci-sion of osteomyelitic bone till healthy bonemargins are reached. Appropriate antibiotictreatment, based on microbiological tests, isusually needed for weeks to months.

Our patient underwent drainage of thesubcutaneous pus and debridement of thewound. The bone was not excised as a veryextensive area of bone seemed to be involvedon the x ray films, and the outer table lookedintact at surgery. Multiple pockets of pus andgranulation tissue were seen in the subcutan-eous plane. Pus smear showed Gram positive,branching filaments. There was a heavy growthof aerobic actinomycetae on Lowenstien-Jensen medium, and on Sabouraud dextroseagar, suggestive of nocardia, which was sensi-tive to co-trimoxazole and penicillin. Therewas no growth of mycobacteria or other patho-gens. The histopathological examination re-vealed dense infiltrate of vascular granulationtissue and exudate (with no granulomata, orcaseation), suggestive of chronic non-specificinflammation.

Q3: What is the optimal treatment of thiscondition?The natural history of primary cutaneousnocardial disease is not known. As cure withsurgical debridement alone occurs in only onethird of cases, drug therapy is recommended inall patients.1 The optimal antibiotic therapy fornocardiosis has not been established.Trimethoprim-sulfamethoxazole acts syner-gistically against most strains of nocardia (invitro),2 and so also minocyclin, amikacin, andimipenem.3 Our patient was thus treated withsulphonamides and amikacin along with surgi-cal debridement. The duration of therapy fornocardiosis varies from three months to oneyear with the type and extent of the disease.1

Considering the chronicity of the disease andextensive bony involvement in our patient, aprolonged course of therapy (co-trimoxazolefor one year) was advised.

DiscussionNocardia are soil saprophytes that usuallycause respiratory infection in immunocompro-mised hosts, and extrapulmonary lesions mayfollow metastatic spread from the pulmonaryfocus. However solitary, extrapulmonary, le-sions, involving skin and subcutaneous tissue,occur in significant number of immuno-competent patients after direct inoculation. In




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primary cutaneous nocardiosis a history oflocal trauma, with soil contamination, isfrequently present and commonly occurs in theextremities in adults (for example gardeningaccident victims).1

Two forms of nocardial skin infection havebeen described4—the acute lymphangitic formand chronic actinomyecetoma—with forma-tion of nocardia grains (aggregates of fila-ments). The main sign of infection is the devel-opment of firm subcutaneous swelling, butlater draining sinus tracts form, which dis-charge serosanguineous material and grains ofnocardia onto the skin surface; bone involve-ment occurs by extension.4 The characteristichistopathological response to nocardial infec-tion is the production of chronic inflammatoryexudate without extensive fibrosis, caseation,or granuloma.

In reported cases of primary cutaneousnocardiosis after inoculation, there is seldomany evidence of impaired immune response ofthe host5; and local inflammation and lym-phadenopathy usually follows. Initial failure ofthese mechanisms to eliminate all organisms,and confinement to a local site, may subse-quently lead to the development ofactinomyecetoma.4 The factors aVecting thischange from acute to chronic phase areunclear; but it is proposed that the host’simmune response as well as the ability of theorganism to lose their cell wall structure,5 mayaVect this transformation. In our case, the longincubation period after inoculation, and subse-quent chronicity of the disease, may be due tothe transiently altered immune status.

In conclusion, when a patient presents withchronic, non-healing sinuses of the scalp,nocardiosis must be considered in the diVeren-tial diagnosis, especially if there has been a his-tory of trauma even in the remote past andspecific cultures should be asked for.

Final diagnosisActinomyecetoma form of primary cutaneousnocardiosis of scalp with involvement of skullbones.

1 Wallace RJ Jr. Infections caused by actinomycetes: nocardio-sis. In: Kelley WN, ed. Textbook of internal medicine. Vol. 2.Philadelphia: JB Lippincott, 1989: 1598–600.

2 Smego RA Jr, Moeller MB, Gallis HA. Trimithoprim-sulfamethoxazole therapy for nocardia infections. ArchIntern Med 1983;143:711–18.

3 Goldstein FW, Hartefort B, Acar JF. Amikacin containingregimens for treatment of nocardiosis in immunocom-pramized patients. J Clin Microbiol 1987;6:198–200.

4 Hay RJ. Nocardial infection of the skin. Journal of Hygiene1983;91:385–91.

5 Beaman BL, Scates SM. Role of L forms of Nocardia caviaein the development of chronic myecetomas in normal andimmunodeficient murine models. Infect Immun 1981;33:893–907.

An unusual complication of carcinoma ofthe caecum

Q1: What abnormality is seen on thecomputed tomogram in fig 1 (see p 438)?The scan shows the characteristic appearanceof widespread gas formation in the soft tissuesof the thigh and pelvis.

Q2: What is the lethal abnormalitypresent on the computed tomogram infig 2 (see p 438)?The striking appearance of gas is seen withinthe great vessels and the apex of the rightventricle.

Q3: What is the underlying diagnosis andwhat are the treatment options for thiscondition?Postmortem examination confirmed the diag-nosis of necrotising myositis with a Duke’s Ccarcinoma of the caecum. Culture of tissuefrom the gluteal region grew Clostridiumsepticum. The main treatment is by early andwidespread surgical excision of all aVected tis-sue. Other treatment options are describedbelow.

BackgroundGas gangrene is a rapidly developing, spread-ing infection of muscle by toxin producingclostridial species, which are anaerobic Grampositive spore forming bacilli found in soil andthe gastrointestinal tract of humans andanimals.1 Most cases are caused by C perfrin-gens type A. Infection in man is usuallysecondary to trauma. Rarely a non-traumaticprimary myonecrosis can occur. This iscommonly due to infection with the relativelyaerotolerant C septicum that allows infection ofhealthy tissue. Intestinal tract abnormalitiesare the major predisposing conditions. Co-lonic neoplasm is the most common of theseand seen in up to 88% of patients with C septi-cum bacteraemia.2 Approximately one third ofcases of spontaneous clostridial gangrene arecaused by C septicum (59 cases reported in theliterature between 1969 to 1977). The organ-ism produces several toxins but the á-toxin isparticularly important causing haemolysis andtissue necrosis. Sudden onset of severe pain atthe site of infection is often associated with amarked tachycardia out of proportion to anypyrexia Prognosis is improved by prompt rec-ognition of the condition. The diagnosis maybe confirmed by Gram stain of wounddischarge or needle biopsy and radiology forearly detection of intramuscular gas. Medicaltreatment is supportive to combat dehydra-tion, shock, and acute tubular necrosis. In vitrodata suggest that C septicum is susceptible to awide range of antibiotics and penicillin,

Learning pointsx Primary cutaneous nocardiosis can

occur in an immunocompetent host.

x In a case of chronic infection of boneand subcutaneous tissue, with multiplesinuses, nocardiosis should beconsidered in the diVerentialdiagnosis.

x Chronic nocardial skin infectioncan manifest, after a long periodof incubation, after primaryinoculation.




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clindamycin, or metronidazole should all beeVective.3 Hyperbaric oxygen has a bacterio-cidal eVect on most clostridial species and caninhibit further toxin production. In vitro, Csepticum is more resistant to the lethal eVects ofhyperoxia in cell free systems.4 The use ofantitoxin antibodies raised against the á-toxinremains controversial. Early surgical excisionof all aVected muscle is the essential life savingmanagement. The overall mortality for gasgangrene is between 11% and 31% butbetween 67% and 100% for C septicuminfection.

The radiological imaging performed imme-diately before the cardiovascular collapsegraphically illustrates the widespread gas for-mation both at the site of initial infection andbeyond. It is striking that the patient was able

to maintain her cardiac output in the face of theappearance on computed tomography. Thesubsequent electromechanical dissociation wasin retrospect a predictable and irrevocableevent.

Final diagnosisGas gangrene caused by C septicum infection.

1 Maclennan JD. The histotoxic clostridial infections of man.Bacteriological Reviews 1962;26:177–276.

2 Stevens DL, Musher DM, Watson DA, et al. Spontaneous,nontraumatic gangrene due to Clostridium septicum. RevInfect Dis 1990;12:286–96.

3 Brazier JS, Levett PN, Stannard AJ, et al. Antibiotic suscep-tibility of clinical isolates of clostridia. J AntimicrobChemother 1985;15:181–5.

4 Hill GB, Osterhout S. Experimental eVects of hyperbaricoxygen on selected clostridial species. I. In-vitro studies. JInfect Dis 1972;125:17–25.




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metabolic acidosis in an afro-caribbean man with

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