Pheochromocytoma Developed in a Boy with Multiple Endocrine Neoplasia Type 2A Confirmed by the RET Proto-oncogene Mutation

Abstract

A 9-year-old boy presented with increased sweating and abdominal pain. His mother and uncle had been diagnosed with bilateral pheochromocytoma and medullary thyroid carcinoma. Magnetic resonance imaging of the boy's abdomen revealed a 7.5 cm×7.0 cm×6.0 cm mass with a thick peripheral enhancing wall and fluid-fluid level at the right suprarenal region. His ¹²³I-meta-iodobenzylguanidine (MIBG) scan showed a large mass with increased MIBG uptake in the right adrenal gland. The levels of serum norepinephrine, urine epinephrine/norepinephrine, metanephrine, and vanillylmandelic acid were elevated. He, his mother, and two sisters tested positive for the known mutation of multiple endocrine neoplasia type 2A, Cys634Tyr in RET proto-oncogene. Laparoscopic tumor excision and right adrenalectomy were performed. Final diagnosis was pheochromocytoma with malignant behavior, based on adrenal gland scoring scale. However, there was no overt metastasis. After surgery, his symptoms resolved and abnormal laboratory tests were normalized.