MEN syndrome is an autosomal dominant (AD) predisposition to developing multiple endocrine tumors.
Points to remember:
- Parathyroid hyperplasia is common to Men I and Men IIa syndrome.
- Medullary carcinoma of thyroid is common to MEN IIa and MEN IIb syndrome.
- MEN I occurs due to mutation in Menin I gene located on chromosome 11q.
- MEN II occurs due to mutation in Menin II gene located on choromsome 10q.
- MEN IV (similar to MEN I) occurs due to mutation in CDKN1B located on chromosome 12p.
MEN I or MEN 1 (Wermer’s syndrome)
Mnemonic: 3 Ps
- Parathyroid hyperplasia
- Pancreatic islet cell tumor (Zollinger-Ellison syndrome in 50% and Insulinoma in 20%)
- Pituitary tumors
MEN II or MEN 2
Mnemonic: 2 Cs
Associated mutation: RET proto-oncogene
- Catecholamine releasing tumor: Pheochromocytoma
- Calcitonin releasing tumor: Medullary carcinoma of thyroid
Component specific to MEN IIA and MEN IIB:
- MEN IIA or 2A (Sipple’s syndrome): Parathyroid hyperplasia (hyperparathyroidism)
- MEN IIB or 2B (also called MEN III): Mucosal neuromas and Marfanoid habitus
MEN IV or MEN 4
MEN IV occurs due to mutation in CDKN1B.
Men IV syndrome is clinically indistinguishable from MEN I syndrome. In addition, these may have:
- Reproductive organ tumors (e.g. testicular tumors, neuroendocrine cervical carcinoma)
- Adrenal + Renal tumors
Endocrinology: Adult and Pediatric By J. Larry Jameson, Leslie J. De Groot