DISCUSSION

Anatomy

• Pancreas: head, uncinate process, neck, body, tail

• Pancreatic duct (Wirsung): joins the CBD at ampulla of Vater enters 2nd part of duodenum at duodenal papillae

• Accessory duct (Santorini): opens into the duodenum

Anatomy

• Pancreatic gland: – Lobulated– Digestive hormones

• Islets of Langerhans: – α cells secrete glucagon(increase Glucose in blood)– β cells secrete insulin (decrease Glucose in blood)– δ cells secrete somatostatin and Gastrin

(regulates/stops α and β cells)– PP cells secrete pancreatic polypeptide

Insulinoma• low frequency, insulinoma (a tumor of pancreatic β-cells) is

the most common type of pancreatic endocrine tumors.• annual incidence of 1 to 4 per million• insulinomas are sporadic, small (90% ≤2 cm), solitary (90%)

and benign (>90%)• At presentation, 50% of patients are over 50 years • Median duration of symptoms of 18 months.• Insulinoma has a female preponderance of 59% and, at

diagnosis a 5% rate of malignancy• About 8% of insulinoma patients are diagnosed with

multiple endocrine neoplasia type 1 (MEN-1)

Insulinoma - An Atypical Presentation: Case Report and Literature ReviewRassauoli, Lai, Sargeant (University of Toronto Medical Journal)

volume 82, number 1, December 2004

Insulinoma - An Atypical Presentation: Case Report and Literature ReviewRassauoli, Lai, Sargeant (University of Toronto Medical Journal)

volume 82, number 1, December 2004

INSULINOMA

• endocrine tumor of the pancreas derived from beta cells that ectopically secretes insulin, which results in hypoglycemia.

• 40–50 years. • Small; 90% are < 2 cm• not multiple (90%)• 5–15% are malignant• distributed throughout the head, body, and tail

NEUROGLYCEMIC SYMPTOMS

• The most common clinical symptoms– confusion, headache, disorientation, visual

difficulties, irrational behavior, or even coma.– sweating, tremor, and palpitations

Fast up to 72 h with serum glucose, C-peptide, and insulin measurements every 4–8 h

<40 mg/dL

CRITERIA FOR DIAGNOSIS

• Insulin level >6 µU/mL; blood glucose is <40 mg/dL

• Elevated C-peptide and serum proinsulin level• Insulin/glucose ratio >0.3• Decreased plasma B-hydroxybutyrate level

EXOGENOUS INSULIN

• (N) Proinsulin levels • ↓ C-peptide levels • (+) Antibodies to insulin • Sulfonylurea

DIAGNOSTIC TECHNIQUES

• CT scanning • Endoscopic ultrasound • Arteriography with catheterization of small

arterial branches of the celiac system combined with calcium injections

DIFFERENTIALS

• Reactive hypoglycaemia• Functional hypoglycaemia with Gastrectomy• Adrenal Insufficiency• Hypopituitarism• Hepatic Insufficiency• Manchausen syndrome (insulin self-injections)• Nonislet cell tumor causing hypoglycaemia• Surreptitious administration of insulin or OHAs

MANAGEMENT

CONSERVATIVE MANAGEMENT• Intake of small frequent meals that are rich in

carbohydrates• Strenuous exercise should be avoided • Medical treatment

• Diazoxide - nondiuretic benzothiadiazine - stimulate b-cell adrenergic receptors decreasing insulin release - standard dose: 150-450mg daily, often divided into doses every 8 hours - side effects: sodium and water retention, hirsutism

SURGICAL MANAGEMENT

Surgical resection - treatment of choice

• Enucleation of the insulinoma - performed in patients who have a solitary tumor that

is not encroaching on the pancreatic duct

• Distal pancreatectomy - performed en-bloc along with resection of the spleen- makes the operation short and easy- tumors are often present in the tail and body of the

pancreas

SURGICAL MANAGEMENT

• Whipple procedure (pancreaticoduodenectomy) - may be required if the tumor is in close

proximity to major ductal structures

• Warshaw's technique- spleen may be preserved by maintaining the

integrity of the short gastric vessels and the left gastro-epiploic vessels

SURGICAL MANAGEMENT

Complications:

pancreatic fistula persistent hyperinsulinism bile leak and prolonged gastric ileus injury to the spleen

SURGICAL MANAGEMENT

• New TechniquesCryoablationLaparoscopic pancreatic surgery