Multiple Endocrine Neoplasia Type 2A Patient with Metastatic Medullary Thyroid Carcinoma and Unilateral Multicentric Pheochromocytoma: A Case Report and Literature Review | Insight Medical Publishing

Introduction: Multiple endocrine neoplasia 2A (MEN2A) is an autosomal dominant syndrome associated with germline mutations in the RET proto-oncogene that may lead to medullary thyroid carcinomas (MTC), pheochromocytomas, and parathyroid adenomas. Patients generally present between the ages of 20 and 30 years. MEN2 patients are stratified for risk based upon the RET mutation, and a genotype-phenotype correlation exists. Case Report: We describe a 36-year-old male recently diagnosed with MEN2A syndrome and RET oncogene mutation [c.1900T>C;p.Cys634Arg], which is a high risk category. He had elevated calcitonin, calcium, parathyroid hormone, and alkaline phosphatase levels with decreased ionized calcium. 24-hour urine testing showed elevated metanephrines and catecholamines. Imaging studies showed a right adrenal mass and multicentric thyroid nodules with a mass adherent to the right inferior posterior thyroid lobe. Right adrenalectomy histologic evaluation revealed multicentric pheochromocytomas in the right adrenal gland. Total thyroidectomy with bilateral central and lateral neck dissections confirmed multicentric MTC metastatic to one right lateral neck lymph node. Although only one parathyroid gland was removed, the findings were suggestive of parathyroid adenoma. Discussion and Conclusion: This case is remarkable for the relatively advanced patient age for presentation with this syndrome given the high-risk category as well as multifocality of the associated neoplasms. The general pathologist should be aware of the MEN2 risk stratification categories based on molecular profiling and the implications on patient care.