Case PresentationCase PresentationAaron M. ChengAaron M. Cheng

UCHSCD Department of SurgeryUCHSCD Department of SurgeryDecember 18, 2006December 18, 2006

48 year old morbidly obese woman with 2 48 year old morbidly obese woman with 2 year history of symptoms occurring after year history of symptoms occurring after exercise or missed meals.exercise or missed meals.

Episodes of warmth, diaphoresis, Episodes of warmth, diaphoresis, tremulousness, vision changes, confusion, & tremulousness, vision changes, confusion, & headacheheadacheReferred to UCH after several recurrences of Referred to UCH after several recurrences of symptomatic hypoglycemia and the patientsymptomatic hypoglycemia and the patient’’s s inability to keep her blood sugars elevated as inability to keep her blood sugars elevated as an outpatientan outpatient

PMHPMHBB--thalassemiathalassemia trait, GERD, Depression, trait, GERD, Depression, ObesityObesity

PSHPSHHysterectomy (2006); Lap gastric banding Hysterectomy (2006); Lap gastric banding (2005); Lap (2005); Lap cholycholy (2003); C(2003); C--sectionsection

MEDSMEDSLexaproLexapro, , NexiumNexium, , CarafateCarafate, , ColaceColace

FH: noncontributoryFH: noncontributory——no no hxhx of MENof MENSH: SH: TobTob–– 15 15 pkpk yr yr hxhx; ETOH; ETOH——socially; socially; nonnon--healthcare worker at hospitalhealthcare worker at hospital

PEPEUnremarkable except for morbid obesity (BMI Unremarkable except for morbid obesity (BMI 56). No palpable masses in abdomen.56). No palpable masses in abdomen.

72 hour fasting study initiated UCH72 hour fasting study initiated UCHLab results:Lab results:

Fasting glucoseFasting glucose 41 mg/41 mg/dLdL (70(70--105)105)CC--peptidepeptide 3.1ng/mL3.1ng/mL (0.8(0.8--3.5)3.5)InsulinInsulin 8 8 mcIU/mLmcIU/mL (2(2--23)23)SulfonylureaSulfonylurea NegNeg

CT scan: small CT scan: small hypodensityhypodensity in neck of in neck of pancreas, possible fat pancreas, possible fat invaginationinvagination but but cannot exclude small cannot exclude small insulinomainsulinomaUpper EUS: Small round Upper EUS: Small round hypoechoichypoechoicmass (18mm X 10mm) identified in mass (18mm X 10mm) identified in pancreatic body with wellpancreatic body with well--defined borders; defined borders; lesion abutted but did not invade lesion abutted but did not invade splenicsplenicart.art.FNA suggested FNA suggested neuroendocrineneuroendocrine tumortumor

Patient underwent distal Patient underwent distal pancreatectomy/splenectomypancreatectomy/splenectomywith tumor location confirmed by with tumor location confirmed by intraoperativeintraoperative ultrasoundultrasoundFinal Diagnosis: Benign Final Diagnosis: Benign InsulinomaInsulinoma

PostPost--op, pt. had resolution of op, pt. had resolution of neuroglycopenicneuroglycopenic symptoms symptoms and serum glucoses in range and serum glucoses in range of 100of 100--130130Pathology confirmed 1.5 cm Pathology confirmed 1.5 cm wellwell--circumscribed circumscribed neuroendocrineneuroendocrine pancreatic pancreatic tumor with neg. margins; tumor with neg. margins; peripancreaticperipancreatic LN (0/6) LN (0/6) negativenegative

InsulinomaInsulinoma: Most common pancreatic : Most common pancreatic neuroendocrineneuroendocrinetumortumor

Incidence: 4 cases per millionIncidence: 4 cases per million--person yearsperson yearsMedian age at Median age at dxdx: 47 yrs (8: 47 yrs (8--82yrs)82yrs)Slight female preponderance (59%)Slight female preponderance (59%)Majority of cases are solitary, benignMajority of cases are solitary, benign——10% malignant10% malignant

Diagnosis of Diagnosis of InsulinomaInsulinoma1935 classic report by Whipple & Franz, 1935 classic report by Whipple & Franz, Adenoma of Adenoma of islet cells with islet cells with hyperinsulinismhyperinsulinism. Am . Am SurgSurgWhippleWhipple’’s Triad:s Triad:

Signs & symptoms of hypoglycemiaSigns & symptoms of hypoglycemiaSerum glucose < 45 mg/Serum glucose < 45 mg/dLdL at time of symptomsat time of symptomsRelief of symptoms by oral or IV glucose administrationRelief of symptoms by oral or IV glucose administration

NeuroglycopenicNeuroglycopenic symptoms: confusion, blurred vision, symptoms: confusion, blurred vision, weakness, headache, & autonomic symptomsweakness, headache, & autonomic symptoms–– anxiety, anxiety, sweating, hunger, palpitationssweating, hunger, palpitationsSymptoms often present for 2Symptoms often present for 2--3 years before diagnosis3 years before diagnosis

Diagnostic test: supervised 72Diagnostic test: supervised 72--hr fasthr fast

Patients observed for signs & symptoms of Patients observed for signs & symptoms of hypoglycemia with simultaneous blood draws for hypoglycemia with simultaneous blood draws for blood glucose, insulin, and Cblood glucose, insulin, and C--peptide.peptide.Test positive when pt. develops symptoms and Test positive when pt. develops symptoms and BG < 40mg/dLBG < 40mg/dLInappropriately high insulin level with Inappropriately high insulin level with hypoglycemia secure diagnosis (hypoglycemia secure diagnosis (insulinsul--glucgluc ratio ratio > 0.3)> 0.3)70% of patients with 70% of patients with insulinomainsulinoma develop develop hypoglycemic symptoms within 24 hrs; 98%, hypoglycemic symptoms within 24 hrs; 98%, within 72 hrswithin 72 hrs

Tumor imagingTumor imaging

CT scan: CT scan: senstivitysenstivity for prefor pre--op localization op localization varies: 11varies: 11--73%73%

MultiphasicMultiphasic CT (arterial, pancreatic, PV CT (arterial, pancreatic, PV phase) may enhance identificationphase) may enhance identification

63% identified using 63% identified using multiphasicmultiphasic CT in Mayo Clinic CT in Mayo Clinic studystudyMost tumors Most tumors hyperenhancehyperenhance & seen better in early & seen better in early phase imagesphase images

MRI: may be better than CTMRI: may be better than CT–– reported to reported to detect detect insulinomasinsulinomas in 85%in 85%--92% cases92% cases

EUSEUS——sensitivity between 70%sensitivity between 70%--95% for 95% for insulinomainsulinoma detectiondetection

Operator dependent and sensitivity decreases Operator dependent and sensitivity decreases for tumors at pancreatic tailfor tumors at pancreatic tail

Invasive tests Invasive tests Angiography: 36%Angiography: 36%--55% sensitivity55% sensitivityTranshepaticTranshepatic portal venous sampling: 55%portal venous sampling: 55%--100%100%Selective arterial calcium stimulation: Selective arterial calcium stimulation: sensitivity report of 94%sensitivity report of 94%

InsulinomaInsulinoma treatment: surgical removaltreatment: surgical removal

Surgical proceduresSurgical proceduresPancreaticoduodenectomyPancreaticoduodenectomyDistal Distal pancreatectomypancreatectomy +/+/-- splenectomysplenectomyEnucleationEnucleationMinimally invasive surgery: not indicated for large or Minimally invasive surgery: not indicated for large or malignant tumors or in patients with MEN 1malignant tumors or in patients with MEN 1

IntraIntra--op ultrasound: important adjunct to surgeryop ultrasound: important adjunct to surgerySerum glucose typically rises and peripheral and Serum glucose typically rises and peripheral and portal vein insulin levels normalize (10portal vein insulin levels normalize (10--86 86 pmolpmol/L) within 20 min. after resection/L) within 20 min. after resection

Selected referencesSelected referencesCurrent Problems in Surgery vol. 43 no. 10; Oct 2006Current Problems in Surgery vol. 43 no. 10; Oct 2006Am Am SurgSurg 1935; 101:12991935; 101:1299--355355AJR 2003; 181:755AJR 2003; 181:755--8080Radiology 1991; 178:237Radiology 1991; 178:237--4141World J World J SurgSurg 2002;26:10572002;26:1057--6565

The EndThe End