Multiple Endocrine Neoplasia

Question 1

What does MEN stand for?

What does it involve?

What are symptoms?

What are the different types?

Answer 1

Multiple endocrine neoplasia

Two endocrine glands; tumors may be either benign or malignant (metastasis)

Symptoms depend on the gland involved

MEN1, MEN2A, MEN2B

Question 2

Which MEN is more common?

Is it autosomal dominant or recessive?

Answer 2

MEN1 most common

MEN2A more common than MEN2B

Autosomal dominant

Question 3

MEN tumors arise from ____ group of cells.

What do these cells do?

Answer 3

Amine precursor uptake and decarboxylation (APUD)

They are a diffuse system of neruoendocirne cells distributed throughout the body and allow multiple endocrine organs to be affected

APUD denotes the capacity of theses cells to synthesize and secrete biogenic amines formed throughout the activity of L-dopa decarboxylase

Question 4

Abnormal mass of tissue, growth exceeds and is uncoordinated with that of normal tissue; persists after cessation of stimuli

Increase number of cells

Increase size of cells

Answer 4

Neoplasm

Hyperplasia

Hypertrophy

Question 5

Tumors associated with MEN1

Answer 5

Pituitary adenoma
Parathyroid adenoma
Carcinoid tumor
Pancreatic endocrine tumor

Question 6

Tumors associated with MEN2A

Answer 6

Medullary thyroid carcinoma
Parathyroid adenoma
Bilateral phaeochromocytoma

Question 7

Tumors associated with MEN2B

Answer 7

Neuronal
Medullary carcinoma of the thyroid
Phaeochronocytoma

Question 8

MEN1 is also called _____.

What is its mutation and what does it cause?

What are its three types of tumors?

Answer 8

Wermer Syndrome

Mutation in Menin protein: tumor suppressor -> mutation causes unregulated cell division

Parathyroid, pancreas, pituitary

Carcinoid (male pt develop carcinoid in thymus; female in bronchial carcinoids)

Question 9

Where is a pituitary adenoma confined to?

Answer 9

Confined to the sella turcica; erode the sella turcica and expand

Question 10

Symptom of a pituitary adenoma in MEN1

Answer 10

Acromegaly (increased secretion of GH)

Question 11

What are the three ways to diagnose MEN1?

Answer 11

Clinical: two or more MEN1 associated tumors

Familial: pt with one MEN1 associated tumor plus a first degree relative with MEN1 dx

Genetic: asymptomatic carrier of MEN1 mutation (no biochemical manifestation)

Question 12

Describe MEN1 parathyroid

Answer 12

Most frequently involved organ

Hyperparathyroidism is first manifestation of the syndrome: associated with hyperplasia of all 4 glands

Question 13

Describe MEN1 endocrine pancreas

Answer 13

Neoplasticism transformation of pancreatic islet cells; 2nd most common manifestation of MEN1

Gastrinoma: most frequent

Insulinoma: 2nd most common

Glucagonoma, somatostatinoma, vasoactive intestinal polypeptide-secreting tumors (VIPomas)

Question 14

Describe MEN1 pituitary

Answer 14

Functionally active and secrete prolactin

Hyperprolacinemia: 3rd most common manifestation of MEN1; causes galatorrhea and amenorrhea in females; impotence in males

MEN1 pt may develop tumors secreting ACTH (Cushing), GH (acromegaly)

MEN1 pts have increase frequency of both functional and nonfunctional adrenal cortical hyperplasia of adenomas

Question 15

What is the treatment for MEN1?

Answer 15

Surgical resection of hyperplastic PT, pituitary adenoma

Pharmacotherapy: bromocriptine for prolactinomas; octreotide for acromegaly

Pancreatectomy

Question 16

MEN2 is caused by what mutation?

What is the most common sign?

What is the normal fx of C cells?

What do 50% of pts with MEN2 develop?

What type of MEN has the highest mortality?

Answer 16

Mutation of RET protooncogene

Malignant transformation of parafollicular cells (C cells) in thyroid-> medullary thyroid carcinoma (MTC)

C cells normally elaborate calcitonin and are scattered throughout thyroid gland

Pheochromocytoma of adrenal gland

MEN2B

*histology shows hyperplasia of C cells

Question 17

What is pheochromocytoma?

What is is a common system?

Answer 17

Tumor of the adrenal gland due to MEN

Hypertension unresponsive to medication

Question 18

MEN 2A causes ____.

Describe MEN2A

What is the progression of parafollicular C cells?

What hormones do C cells abnormally express in this syndrome?

Answer 18

Sipple syndrome

Neoplastic transfromation of parathyroid, thyroid parafollicular C cells, and adrenal medulla

Parafollicular C cells progress through a state of C cell hyperplasia to nodular hyperplasia to malignant degeneration over time

Somatostatin, TRH, VIP, POMC, carcinoembryonic antigen (CEA), neurotensin

Question 19

What are conditions associated with MEN2A (sipple syndrome)?

Answer 19

Pheochromocytoma associated with MEN2A secrete greater amount of epinephrine than sporadic pheochromocytomas

Hyperparathyroidism: MEN2A similar to MEN1 but less frequent

Cutaneous lichen amyloidosis: itchy skin condition

Question 20

Skin lesion associated with MEN2a

Pruritic, scaly, popular, pigmented, located in interscapular region or on extensor surfaces of extremities

Answer 20

Cutaneous lichen amylidosis

Question 21

Describe MEN2B and symptoms

Answer 21

Younger age of death
MTC
Pheochromocytoma
Mucosal neuromas
Intestinal ganglioneuromas

Marfanoid body habitus: symptoms resembling those of Marfan syndrome including long limbs, crowded oral maxilla, arachnodactyly, hyperlaxity

(Hyperparathyroidism is not associated with MEN2B)