Most common islet cell tumour in MEN 1 is Gastrinoma

Question 88

Most common islet cell tumour in MEN 1 is

a.       Gastrinoma

b.      Insulinoma

c.       Glucagonoma

d.      Somatostatinoma

Answer

a. Gastrinoma

Reference

Schwartz 7^th Edition Page 1686

Sabiston 15^th Edition Page 685

Harrison 16^th Edition Page 2231

Robbins 5^th Edition Page 1170

Quality

Spotter

Status

Repeat

QTDF

Harrison

Discussion

Neoplasia of the pancreatic islets is the second most common manifestation of MEN 1 and tends to occur in parallel with hyperparathyroidism. Increased pancreatic islet cell hormones include pancreatic polypeptide (75 to 85%), gastrin [60%; Zollinger-Ellison syndrome (ZES)], insulin (25 to 35%), vasoactive intestinal peptide (VIP) (3 to 5%; Verner-Morrison or watery diarrhea syndrome), glucagon (5 to 10%), and somatostatin (1 to 5%). The tumors rarely produce adrenocorticotropin (ACTH), corticotropin-releasing hormone (CRH), growth hormone-releasing hormone (GHRH), calcitonin gene products, neurotensin, gastric inhibitory peptide, and others. Many of the tumors produce more than one peptide. The pancreatic neoplasms differ from the other components of MEN 1 in that approximately one-third of the tumors display malignant features, including hepatic metastases (Chap. 93).

Explanation

Of the choices given, the most Common Pancreatic Tumour in MEN I is Gastrinoma.

Comments

Multiple Endocrine Neoplasia (MEN) Syndromes
Type	MEN 1	MEN 2		Mixed Syndromes
		MEN 2A	MEN 2B
Name	Wermer’s Syndrome	Sipple’s Syndrome
Gene	11q 11-13	RET
Parathyroid	Parathyroid hyperplasia or adenoma	Parathyroid hyperplasia or adenoma		Familial pheochromocytoma and islet cell tumor von Hippel-Lindau syndrome, pheochromocytoma, and islet cell tumor Neurofibromatosis with features of MEN 1 or 2 Myxomas, spotty pigmentation, and generalized endocrine overactivity in a single family
Pancreas	Islet cell hyperplasia, adenoma, or carcinoma
Pituitary	Pituitary hyperplasia or adenoma
Thyroid	C Cell Hyperplasia	Medullary Thyroid Carcinoma	MTC
Adrenal	Rarely Cortical Involvement	Pheochromocytoma	Pheochromocytoma
Others	Other less common manifestations: foregut carcinoid, , subcutaneous or visceral lipomas, dermal angiofibromas or collagenomas	Cutaneous lichen amyloidosis Hirschsprung disease Familial Medullary Thyroid Carcinoma	Mucosal and gastrointestinal neuromas Marfanoid features

Tips

This is one of the most repeated topics for AIPG. There will be 2 to 3 questions every year

MEN

Ä     Pancreatic islet cell tumors are diagnosed by identification of a characteristic clinical syndrome, hormonal assays with or without provocative stimuli, or radiographic techniques. One approach involves annual screening of people at risk with measurement of basal and meal-stimulated levels of pancreatic polypeptide to identify the tumors as early as possible; the rationale of this screening strategy is the concept that surgical removal of islet cell tumors at an early stage will be curative. Other approaches to screening include measurement of serum gastrin and pancreatic polypeptide levels every 2 to 3 years, with the rationale that pancreatic neoplasms will be detected at a later stage but can be managed medically, if possible, or by surgery. High-resolution, early-phase computed tomography (CT) scanning provides the best noninvasive technique for identification of these tumors, but intraoperative ultrasonography is the most sensitive method for detection of small tumors.

Ä     ZES is caused by excessive gastrin production and occurs in more than half of MEN 1 patients with pancreatic islet cell tumors. Clinical features include increased gastric acid production, recurrent peptic ulcers, diarrhea, and esophagitis. The ulcer diathesis is refractory to conservative therapy such as antacids. The diagnosis is made by finding increased gastric acid secretion, elevated basal gastrin levels in serum [generally >115 pmol/L (200 pg/mL)], and an exaggerated response of serum gastrin to either secretin or calcium. Other causes of elevated serum gastrin levels, such as achlorhydria, treatment with H2 receptor antagonists or omeprazole, retained gastric antrum, small-bowel resection, gastric outlet obstruction, and hypercalcemia, should be excluded. Gastrin-producing carcinoid-like tumors are frequently present in the duodenal wall.

Ä     Insulinoma causes hypoglycemia in about one-third of MEN 1 patients with pancreatic islet cell tumors. The tumors may be benign or malignant (25%). The diagnosis can be established by documenting hypoglycemia during a short fast with simultaneous inappropriate elevation of serum insulin and C-peptide levels. More commonly, it is necessary to subject the patient to a supervised 72-h fast to provoke hypoglycemia. Large insulinomas may be identified by CT scanning; small tumors not detected by radiographic techniques may be localized by selective arteriographic injection of calcium into each of the arteries that supply the pancreas and sampling the hepatic vein for insulin to determine the anatomic region containing the tumor. Intraoperative ultrasonography can also be used to localize these tumors, but preoperative calcium injection data are helpful in guiding the subtotal pancreatectomy if multiple or no abnormalities are detected by intraoperative ultrasonography.

Ä     Glucagonoma in occasional MEN 1 patients causes a syndrome of hyperglycemia, skin rash (necrolytic migratory erythema), anorexia, glossitis, anemia, depression, diarrhea, and venous thrombosis. In about half of these patients the plasma glucagon level is high, leading to its designation as the glucagonoma syndrome, although elevation of plasma glucagon level in MEN 1 patients is not necessarily associated with these symptoms. The glucagonoma syndrome may represent a complex interaction between glucagon overproduction and the nutritional status of the patient.

Ä     The Verner-Morrison or watery diarrhea syndrome consists of watery diarrhea, hypokalemia, hypochlorhydria, and metabolic acidosis. The diarrhea can be voluminous and is almost always found in association with an islet cell tumor, prompting use of the term pancreatic cholera. However, the syndrome is not restricted to pancreatic islet tumors and has been observed with carcinoids or other tumors. This syndrome is believed to be due to overproduction of VIP, although plasma VIP levels may not be elevated. Hypercalcemia may be induced by the effects of VIP on bone as well as by hyperparathyroidism.