DISCUSSION

Anatomy Pancreas: head, uncinate process, neck, body, tail Pancreatic duct (Wirsung): joins the CBD at ampulla of Vater  enters 2 nd 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)glucagon – β cells secrete insulin (decrease Glucose in blood)insulin – δ cells secrete somatostatin and Gastrin (regulates/stops α and β cells)somatostatin – PP cells secrete pancreatic polypeptidepancreatic 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 Review Rassauoli, Lai, Sargeant (University of Toronto Medical Journal) volume 82, number 1, December 2004

Insulinoma - An Atypical Presentation: Case Report and Literature Review Rassauoli, 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: mg 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 Techniques Cryoablation Laparoscopic pancreatic surgery