De novo mutation in multiple endocrine neoplasia-2B: Family study and review of literature

Multiple endocrine neoplasia (MEN) type 2B is an autosomal dominant syndrom e, which consists of medullary thyroid carcinoma (MTC), pheochromocytoma, a nd mucosal neuromas. Presentation, especially with MTC, is usually early in life and more aggressive than MEN-2A. Recent development in genetic studie s makes the diagnosis and screening more practical and accurate. We report a young fe male who presented to general surgery for the first time at age 14 years with goiter. Histopathology revealed multifocal MTC. Re-evaluation at the age 20 by an endocrinologist revealed a mutation in codon 918 of RE T proto-oncogene, which is consistent with diagnosis of MEN-2B. Further inv estigation revealed that she still has residual disease in the neck and pul monary metastasis. Family screening for RET proto oncogene for father, moth er, brother, and five sisters was negative for RET mutation. Thus, this is a case of MEN-2B with de novo mutation in RET proto oncogene.