157. Multiple endocrine neoplasia (MEN) syndrome

Question 1

Definition

Answer 1

group of inherited diseases caused by proliferation lesions (hyperplasia, adenomas, carcinomas) of multiple endocrine organ

Question 2

Special features to distinguish from sporadic form

Answer 2

• arise in young age
• arise in multiple endocrine organs
• multifocal lesions
• hyperplasia in pretumor state
• more aggressive than sporadic

Question 3

MEN-1

Answer 3

Gene: MEN-1 tumor supressor (loss of function), encodes
protein called menin
Endocrine glands affected (3P)
- parathyroid- hyperparathyroidism
- hyperplasia
- adenomas
- pancreas
- zollinger ellison syndrome
- pituitary
- prolactin secreting macroadenomas
- somatotropin secreting tumor

Question 4

MEN-2A

Answer 4

Gene: gain of function of RET (oncogene)
Endocrine glands affected (ATP):
       - Adrenal medulla
               - pheochromocytomas
      - Thyroid
               - Medullary carcinoma
               - C cell hyperplasia
      - Parathyroid
               - parathyroid hyperplasia

Question 5

MEN-2B

Answer 5

Gene: single amino acid change in RET
Endocrine glands effected:
- thyroid medullary carcinoma (more aggressive than
MEN-2A)
- pheochromocytomas
- NOOOOOO parathyroid hyperplasia
Extraendocrine manifestations
- Ganglioneuromas of mucosal sites (lips, tongue, GI)
- Marfanoid habitus (long bones of axial skeleton
resemble marfan)