Multiple endocrine neoplasia (MEN)

Autosomal dominant disorder

MEN 1 (Wermer's syndrome)

11q13 chromosome

MEN1 gene / menin

Follows knudson's two hit hypothesis

Associated tumors - 3P'S

Anterior Pitutary tumors / Pitutary adenoma (Prolactinoma > Somatotrophinoma > Corticotrophinoma) 

Parathyroid adenoma (Most common tumor overall among MEN1)

Pancreatic tumors (Non functioning pancreatic tumor is more common than Functioning pancreatic tumor) (Among functional pancreatic tumor in MEN 1 Gastrinoma > Insulinoma > Glucaganoma > VIPoma)

Note - Eventhough Gastrinoma is more common than insulinoma in MEN1 syndrome ; Overall incidence of  Insulinoma is more than gastrinoma 

Most common cutaneous tumors in MEN 1 (Angiofibroma > Collagenoma > Lipoma) 

Adrenal cortical tumors

Meningioma

Neuroendocrine tumors (Gastric , Thymic , Bronchopulmonary)

Pheochromocytoma

Carcinoid tumors

MEN 2A (Sipple's syndrome)

10q11.2 chromosome

RET Proto-oncogene

634 , missense , Cys to Arg

Associated tumors -

Medullary thyroid carcinoma

Pheochromocytoma

Parathyroid adenoma

MEN 2B/MEN 3 (Wagenmann-Froboese syndrome / Mucosal neuroma syndrome)

10q11.2 chromosome

RET Proto-oncogene

918 , Met to Thr  {Single Methionine to Threonine substitution in intracellular tyrosine kinase domain}

Associated tumors -

Medullary thyroid carcinoma

Pheochromocytoma

Mucosal neuromas

Medullated corneal nerve fibers

Marfanoid habitus

Megacolon

MEN 4 / MEN X

12p13 chromosome

CDKN1B gene (Cyclin Dependent KiNase inhibitor 1B)

Associated tumors -

Parathyroid adenoma

Pitutary adenoma

Reproductive organ tumor (testicular cancer , neuroendocrine cervical cancer)

Adrenal + Renal tumors

#crackmbbs