A case of multiple endocrine neoplasia type 2B undiagnosed for many years despite its typical phenotype

We report the case of a 24-yr-old man with a typical phenotype of multiple endocrine neoplasia type 2B (MEN 2B). The patient had previously undergone minor surgery to remove multiple tumors on the lip, but he had no further e xaminations. MEN 2B was suspected owing to characteristic multiple ganglion euromatosis when the patient presented with a goiter associated with high l evels of plasma calcitonin and CEA. Aspiration biopsy cytology revealed med ullary thyroid carcinoma (MTC), and abdominal computed tomography and nucle ar scanning with metaiodobenzylguanidine revealed bilateral adrenomedullary tumors. Adrenomedullary function tests showed high levels of serum and uri nary fractionated catecholamines, and genetic analysis showed a point mutat ion in the codon 918 (M918T) of the RET gene. The patient was diagnosed wit h MEN 2B and underwent right adrenalectomy and total thyroidectomy. No dist ant metastasis of the MTC was noted although MEN 2B had remained undiagnose d since the ganglioneuromatosis was first noticed. MEN 2B is a rare heredit ary disorder, but the occurrence of characteristic ganglioneuromatosis was quite helpful in making the diagnosis.