The Characterization of Pheochromocytoma and Its Impact on Overall Survival in Multiple Endocrine Neoplasia Type 2

Context: Pheochromocytoma (PHEO) occurs in 50% of patients with multiple endocrine neoplasia type 2 (MEN2). It is unknown if the presence of PHEO is associated with more aggressive medullary thyroid cancer (MTC). Objective: To present our experience with MEN2 PHEO and evaluate whether PHEO impacts MTC overall survival in patients with RET codon 634 mutations. Design: We performed a retrospective chart review of MEN2 patients at MD Anderson Cancer Center from 1960 through 2012. Patients: The study group comprised 85 patients (group 1) with MEN2-associated PHEO. Of these, 59 patients (subgroup 1) with RET codon 634 mutations were compared to 48 patients (group 2) with RET codon 634 mutations, but without MEN2-associated PHEO. Main Outcome Measures: Of 85 patients with MEN2 and PHEO, 70 had MEN2A and 15 had MEN2B. Median age at PHEO diagnosis was 32 years. The initial manifestation of MEN2 was MTC in 60% of patients, synchronous MTC and PHEO in 34%, and PHEO in 6% of patients. Of patients, 72% had bilateral ...