copyright © 2004 pearson education, inc., publishing as benjamin cummings endocrine surgery

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

Endocrine Surgery

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

Primary Hyperparathyroidism (PHPT)

iPTH

Ca

PHPT

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PHPT

• 0.1-3% of population.

• Common , over 100 000 new cases

diagnosed/y in US.

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PHPT

• Single parathyroid adenoma (80%-90%)

• Double adenomas (2%-15%)

• Asymmetric 4-gland hyperplasia (10%-15%)

• Carcinoma (<1% of patients)

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Symptoms and Signs

• Moans, groans, stones, and bones

• Hypercalcemia

• Bone disease

• Nephrolithiasis

• Hypophosphatemia

• Proximal renal tubular acidosis

• Hypomagnesemia

• Hyperuricemia

• Gout

• Anemia

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Manifestations of Hypercalcemia

• CNS dysfunction

• Muscle weakness

• Bowel hypomotility and constipation

• Peptic ulcer disease

• Pancreatitis

• Acute and chronic renal insufficiency

• Nephrogenic diabetes insipidus

• Distal renal tubular acidosis

• Nephrolithiasis

• Shortening of the QT interval

• Corneal calcium deposition (band keratopathy)

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Imaging

A.J. Coakley, A.G. Kettle and C.P. Wells et al., 99mTc sestamibi a new agent for parathyroid imaging, Nucl Med Commun 10 (1989), pp. 791–794

mm

• commonly used for cardiac imaging

• Avidly taken up by parathyroid tissue

• Reoperative setting

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2002 NIH Workshop on Asymptomatic PHPT

• Serum Ca > 1.0 mg/dL above the upper limit of normal.

• Hypercalciuria (urinary Ca excretion > 400 mg/day) .

• Creatinine clearance that is <30% than that of age-matched normal subjects.

• Bone density at the hip, lumbar spine, or distal radius that is T score <-2.5.

• <50 years old.

• Difficult periodic follow-up.

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IOPTH MEASUREMENTS

• Recorded before resection of any enlarged glands

• Just before excising the gland.

• Postexcision IOPTH levels were measured 10 min or longer after resection of the enlarged parathyroid gland(s).

• A decrease of 50% or more in the IOPTH level was used to define successful parathyroidectomy.

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Why should virtually all patients be considered for surgical intervention?

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•Surgery offers the only cure

•Surgery is of benefit to symptomatic patients

•Surgery is of benefit to “asymptomatic” patients

•Increases bone density and decreases fracture rates

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•Prolongs survival

•Improves neurocognitive symptoms

•92% of patients claim to feel better after parathyroidectomy, even when only 75% claim they felt "bad" before the operation.

•Regression of left ventricular hypertrophy.

•Cure of diabetes.

•Surgical cure rates are high

•Surgery is safe

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Why should virtually all patients be considered for surgical intervention?

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Familial HPTH

• MEN type 1

• MEN type 2A

• Familial Isolated PHPT

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Surgical approach for MEN1

• Parathyroidectomy

• Thymectomy

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Subtotal Vs Total with autotransplantation

• Subtotal parathyroidectomy • Total with autotransplantation

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MEN 2A

• HPT 20-35%

• MTC > 95%

• Pheochromocytoma 42-50%

• Cutaneous lichen amyloidosis

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FIHPT

• Carefully screened for MEN, including a thorough FHx, ret oncogene testing, and exclude Pit &Panc neuroendocrine tumors.

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FIHPT

• Profound hypercalcemia, Nephrolithiasis, and severe osteoporosis.

• No definite genetics have been identified

• Jaw tumors (FIH-JT)

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PHPT in MEN1

• Concurrent ZE syndrome

parathyroidectomy (reducing ca levels can reduce gastrin secretion)

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PHPT in MEN2A

• MEN-2A must be biochemically screened for the presence of pheochromocytoma before parathyroidectomy.

• If present, parathyroidectomy should be delayed until the pheochromocytoma is addressed.

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Demographics of Thyroid Cancer

• ACS est 20,700 new cases of thyroid cancer in U.S. in 2002

• Cause-specific deaths in 2002 est to be 1300

• Occult cancer in autopsy studies reported to 4-35% worldwide

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The New End Point

• The gland should be removed en bloc

• Care should be taken to remove the entire superior pole

• The RLN should be identified and followed to the point where it enters the larynx

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

Nodular hyperplasia

Adenoma

Cyst

Hashimoto thyroiditis

Malignancy

Differential Diagnosis of a Thyroid Nodule

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Risk Factors for Thyroid Cancer

• History of head and neck radiation

• Male sex

• Family history of medullary carcinoma (MEN syndromes)

• Family history of papillary carcinoma

• Hoarseness (vocal cord paralysis)

• Fixation to adjacent structures

• Single, firm, cold nodule

• Nodule> 4cm

• Rapid tumor growth

• Enlarging thyroid nodule(s) on thyroid suppression

• Cervical lymphadenopathy

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AGES AMES DAMES SAG MACIS

Age Age DNA Size Metastasis(Distant)

Grade

Metastasis Age Age Age

Extent Extent Metastasis(Distant)

Grade Completeness of resection

Invasion

Size

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TYPES

Tumors of Follicular Cell Origin

Differentiated

Papillary

Follicular

Hürthle Cell

Undifferentiated

Anaplastic

Tumors of Parafollicular or C-cell Origin

Medullary

Other

Lymphoma

Squamous cell carcinoma,secondary tumors

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MEN 2

• MEN 2A :

• MTC > 95% of the patients

• Pheochromocytoma 42-50%

• Hyperparathyroidism 20-35%

• Cutaneous lichen amyloidosis

• MEN 2B:

• MTC 100%

• Pheochromocytomas 50%

• Ganglioneuromas of the lips, tongue, eyelids, and gastrointestinal tract

• Marfanoid physical (but not cardiac) features

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Biochemistry

• Parafollicular C cells

• CTN

• CEA

• Corticotropin

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Pathology: Amyloid

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CLINICAL PRESENTATION

• Most has already metastasized at the time of diagnosis.

• CLN

• 15% symptoms of upper aerodigestive tract compression or invasion such as dysphagia or hoarseness

• 5% distant disease

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CLINICAL PRESENTATION

• Calcitonin:

• Diarrhea

• facial flushing

• ACTH:

• Cushing's syndrome.

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Genetic screening

• Patients identified as carriers of a RET mutation will develop MTC and should undergo prophylactic Thyroidectomy.

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Treatment

• Total thyroidectomy

• CLN Dissection:

• from the level of the hyoid to the innominate vessels and laterally to the carotid arteries.

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MRND

• Preserve:

• SCM

• Spinal Accessoy N.

• IJV

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Pheo & Para in MEN2A

• MEN-2A must be biochemically screened for the presence of pheochromocytoma before parathyroidectomy.

• If present, parathyroidectomy should be delayed until the pheochromocytoma is addressed.

mm

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

Causes of Cushing’s Syndrome

mm

Cushing’s disease 68

Ectopic ACTH syndrome12

12

Ectopic CRH syndrome<1

<1

Adrenal adenoma 10

Adrenal carcinoma 8

Adrenal cortical hyperplasias

1

Pseudo-Cushing’s Syndrome

1

Major depression

Alcoholism

1

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S & S

• General   Central obesity   Proximal muscle weakness   Hypertension  Headaches  Psychiatric disorders

Skin   Wide (>1 cm) purple striae   Spontaneous ecchymoses   Facial plethora   Hyperpigmentation  Acne  Hirsutism  Fungal skin infections

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S & S• Hypokalemic alkalosis

•  Osteopenia Delayed bone age in children  

• Menstrual disorders, decreased libido, impotence  

• Glucose tolerance, diabetes mellitus  

• Kidney stones  Polyuria  

• Elevated white blood cell count

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

Carcinoid Tumors

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Products of carcinoid tumors

Dopamine Neurokinin A

Histamine Neurokinin B

Polypeptides Corticotropin (ACTH)

Kallikrein Gastrin

Pancreatic polypeptide Growth hormone

Bradykinin Peptide YY

Motilin Glucagon

Somatostatin Beta-endorphin

Vasoactive intestinal peptide Neurotensin

Neuropeptide K Chromogranin A

Substance P Prostaglandins

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5-HIAA

• Definitive diagnosis can be confirmed by the finding of elevated urinary 5-HIAA levels

• Asymptomatic patients ,only 75% sensitive for detecting the presence of 1ry tumors without metastatic disease.

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Chromogranin A

• Elevated in > 80% of patients with carcinoid tumors.

• Elevated level is an independent predictor of an adverse prognosis.

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Diagnostic Modalities

• CT :

• hepatic and lymph node metastases

• SB follow-through:

• kinking of bowel

• smooth luminal filling defect

• Sensitivity:30- 40%.

mm

Capsule Endoscopy

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Diagnostic Modalities

• Somatostatin receptor scintigraphy:

• successfully localize primary and metastatic tumors in approximately 80% of patients

• useful staging procedure before surgical exploration to detect the extent of tumor burden and allow surgical planning.

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Surgery

• 1ry< 1 cm in diameter without evidence of regional lymph node metastasis:

• segmental intestinal resection is adequate.

• Lesions of TI or appendiceal lesios >2cm are best treated by R hemicolectomy.

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Gastrinoma

• Sporadic 75%

• MEN 1 25%

mm

mm

• Peptic acid hypersecretion:

• abdominal pain

• Diarrhea

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MEN 1

• 12% manifest all three Ps

• Screen in patient with PHPT who <50y

• PHPT

• Pancreatic neuroendocrine tumors:

• ZES (54%)

• Insulinoma (21%)

• Pituitary tumors

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Secretin test in gastrinoma

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Insulinoma distribution

• Location:• Virtually all are intrapancreatic.

• Most are solitary (10% multiple)• Diameter:• 10% >2cm• 10% malignant. • 10% MEN-1 (Higher risk of recurrence).

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Another Rule of 10%

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Symptoms

• Whipple triad:• symptoms of hypoglycemia (catecholamine release)• low blood glucose level (40 to 50 mg/ dL)• Relief of symptoms after intravenous administration of

glucose • Neuroglycopenic :confusion, visual change. • Sympathoadrenal : palpitations, diaphoresis, and tremulousness. • Seizure disorder is another common misdiagnosis.

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Localization Techniques True Positives(%)

• Ultrasonography 23

• Octreotide radioimaging (SRS) 86(50%)

• CT 43

• MRI 26

• Endoscopic ultrasonography 82

• Selective angiography 56

• Provocative angiography 65

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Surgery

• Benign:

• Enucleation:

• Malignant(10%):

• Cancer-type operation

• Metastatic, attempt to remove all primary and metastatic tumor to minimize persistent hyperinsulinism.

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Medical therapy

• Indications:

• insulinoma was missed during pancreatic exploration

• Pt not a candidate for or refuses surgery

• Metastatic disease.

• Diazoxide

• Octreotide

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