A case of Papillary Thyroid Carcinoma Combined with Multiple Endocrine Neoplasia Type 24

Multiple endocrine neoplasia (MEN) type 2A is a syndrome of medullary thyroid carcinomas, pheochromocytomas and parathyroid hyperplasia. The simultaneous occurrence of medullary, and papillary, thyroid carcinomas is rare because they are derived from, apparently, different germ layers, the former from the neuroectoderm and the latter from the endoderm. We report a case of a papillary thyroid carcinoma, combined with a medullary thyroid carcinoma, in a patient with MEN type 2A. Molecular genetic studies for screening a RET proto-oncogene mutation revealed a point mutation in codon 631 on chromosome 10, which is reported as highly uncommon in MEN type 2A.