Multiple endocrine neoplasia [MEN] type IIA

This code identifies Multiple Endocrine Neoplasia type IIA, a rare, inherited cancer syndrome characterized by the development of medullary thyroid carcinoma (MTC), pheochromocytoma, and primary hyperparathyroidism. It results from a germline mutation in the RET proto-oncogene.

Assign this code when documentation confirms a diagnosis of MEN type IIA, typically based on genetic testing revealing a RET mutation and/or the presence of the characteristic tumor triad. This code is appropriate for patients undergoing screening, surveillance, or treatment for any component of the syndrome.

• Do not confuse with MEN type I (Wermer's syndrome) or MEN type IIB, which have distinct clinical presentations and genetic bases.
• Code all manifestations of MEN type IIA (e.g., MTC, pheochromocytoma, hyperparathyroidism) in addition to this code.
• Ensure documentation specifies "type IIA" to differentiate from other MEN syndromes.