MULTIPLE ENDOCRINE NEOPLASIA TYPE 2A (MEN 2A) AMONG THREE FILIPINO SIBLINGS

A CASE SERIES

Abstract

CASE
MEN2A is a rare familial cancer syndrome caused by RET proto-oncogene mutations with autosomal dominant inheritance. We describe the cases of three Filipino female siblings. The eldest, 26 years old, was diagnosed with medullary thyroid cancer (MTC) stage II after total thyroidectomy. Surveillance showed increasing serum calcitonin and a right adrenal incidentaloma. Although biochemical tests were normal, histopathologic examination post-adrenalectomy revealed pheochromocytoma. The second, 25 years old, was diagnosed with MTC stage IVA and pheochromocytoma after total thyroidectomy and unilateral adrenalectomy. The youngest, 20 years old, ran an aggressive course. She had MTC Stage IVC and bilateral
pheochromocytoma and underwent total thyroidectomy with modified radical neck dissection and bilateral adrenalectomy. Her calcitonin levels remain >1000 pg/mL, prompting consideration of systemic therapies. Genetic analysis of all three revealed RET mutation (p.Cys634Arg). RET mutation analysis for MEN2 suspected patients should be included to facilitate family screening and prevent disease-related morbidity.