Multiple Endocrine Neoplasia (Men)

Hyperparathyroidism

REF: Harrison’s Internal Medicine 17th ed Chapter 345 Table 345-1, http://en.wikipedia.org/ wiki/Multiple_endocrine_neoplasia

Primary hyperparathyroidism is the most common manifestation of MEN1 Hyperparathyroidism is the earliest manifestation of the syndrome in most MEN1 patients.

• Enteropancreatic tumors are the second most common manifestation of MEN1
• Gastrinomas are the most common enteropancreatic tumors observed in MEN1 patients
• Insulinomas are the second most common enteropancreatic tumors in patients who suffer from MEN1. Unlike gastrinomas, most insulinomas originate in the pancreas bed, becoming the most common pancreatic tumor in MEN1.

MEN 1 is an autosomal dominant disorder due to a defect in 11q13, which encodes for a 610-amino-acid nuclear protein, menin.

Patients with MEN1 develop hyperparathyroidism due to parathyroid hyperplasia in 95–100% of cases, pituitary adenomas in 54–80%, adrenal adenomas in 27–36%, bronchial carcinoids in 8%.

Ref: Harrisons Principles of Internal Medicine, 18th Edition, Page 3060.

Functional pancreatic endocrine tumor in MEN 1 : 54% develope Zollinger-Ellison syndrome, 18% insulinomas, 3% glucagonomas, 3% VIPomas.

Reference:
Harrisons Principles of Internal Medicine, 18th Edition, Page 3060

Ans. is ‘a’ i.e., MEN 1

Answer is B (MEN 2a):

Sipple syndrome refers to MEN Type-HA

Answer is B (Islet cell hyperplasia):

Pituitary islet cell tumors/hyperplasia are associated with MEN- I syndromes and not with MEN II syndromes.

Answer is B: (MCT, Pheochromocytoma, Parathyroid adenomas):

Sipple syndrome refers to MEN Type-IIA and is typically associated with Medullar Carcinoma Thyroid (MCT), Pheochromocytoma and Parathyroid Adenoma/Hyperplasia.

Ans. D: Medullary carcinoma of thyroid

• Parathyroid-Hyperparathyroidism is present in 80-95% of patients. Asymptomatic hypercalcemia is the most common manifestation: about 25% of patients have evidence of nephrolithiasis or nephrocalcinosis. In contrast to sporadic cases of hyperparathyroidism, diffuse hyperplasia or multiple adenomas are more common than solitary adenomas.
• Pancreas-Pancreatic islet cell tumors occur in 60 to 70% of patients. Tumors are usually multicentric.
• Multiple adenomas or diffuse islet cell hyperplasia commonly occurs; such tumors may arise from the small bowel rather than the pancreas. About 30% of tumors are malignant and have local or distant metastases. Malignant islet cell tumors due to MEN 1 syndrome often have a more benign course than do sporadically occurring malignant islet cell tumors.

About 40% of islet cell tumors originate from a beta cell, secrete insulin (insulinoma), and can cause fasting hypoglycemia. Beta-Cell tumors are more common in patients < 40. About 60% of islet cell tumors originate from non­beta-cell elements and tend to occur in patients > 40. Non-beta-cell tumors are somewhat more likely to be malignant

• Pituitary-Pituitary tumors occur in 15 to 42% of MEN 1 patients. From 25 to 90% are prolactinomas. About 25% of pituitary tumors secrete growth hormone or growth hormone and prolactin. Excess prolactin may cause galactorrhea and excess growth hormone causes acromegaly clinically indistinguishable from sporadically occurring acromegaly. About 3% of tumors secrete ACTH, producing Cushing’s disease. Most of the remainder are nonfunctional.

Ans. is b’ i.e., Gastrinoma

Amongst the options provided Gastrinomas are the most common association with MEN I.