Multiple endocrine neoplasia (MEN) type IIa, also known as Sipple syndrome, accounts for most cases of MEN2 and is characterized by:
pheochromocytomas: in 50% of patients, often bilateral, and can be extra-adrenal
medullary thyroid cancer: 100% of patients, aggressive, and may secrete calcitonin
parathyroid hyperplasia: only seen in 20% of patients, and often presents with hypercalcemia and renal calculi
Mnemonic:
PMP
Pathology
Genetics
A small proportion of individuals have a RET D631 proto-oncogene mutation. RET mutation is different from the RET translocation in papillary thyroid carcinoma. The chromosome locus is 10q11.2. 3