MON-392 Bilateral Pheocromocytoma With A Ret Proto-oncogene Mutation

Introduction: Pheochromocytoma is a rare neoplasm, occurring in less than 0.2% percent of patients with hypertension. We present a case of bilateral pheochromocytoma with a RET proto-oncogene mutation. Clinical case: 47 year old male with history of multiple hypertensive crises, 10 kg weight loss in a 3 month period and atrial fibrillation with rapid ventricular rate; heavy tobacco use; and family history of cerebrovascular disease. He presents to the emergency department with fever, right flank ecchymosis, abdominal pain, and blood pressure of 210/110 mmHg (n <120/90 mmHg); thyroid and pulmonary examination were normal. Abdominal CT scan revealed bilateral growth of adrenal glands, which prompted his hospital admission. Total plasma catecholamines were 12159 pg/ml (n <504 pg/ml), predominately epinephrine; 24 hour urine catecholamines measured 1254 µg (n <100 µg), and 24 hour urine metanephrines measured 22485 µg (n <900 µg). Abdominal MRI showed bilateral adrenal tumors; right adrenal gland measuring 3.5 x 4 cm and left adrenal gland 6 x 5 cm; heterogeneous, with cystic features and hyperintensity on T2 weighted images. Patient underwent bilateral adrenalectomy. The pathology report showed bilateral pheochromocytoma without capsular or vascular invasion. Peripheral leukocyte DNA analysis showed a RET proto-oncogene TGC-TAC mutation in codon 634 of exon 11. Postoperative testing showed normal catecholamine and metanephrine levels. Patient presented complete clinical remission. Conclusion: There are several familial disorders associated with adrenal pheochromocytoma, all of which have autosomal dominant inheritance: von Hippel-Lindau syndrome, multiple endocrine neoplasia type 2 and, less commonly, neurofibromatosis type 1. Multiple endocrine neoplasia type 2 is associated with mutations in the RET proto-oncogene. If a patient presents with bilateral adrenal pheochromocytoma but without a history of medullary thyroid cancer or goiter, tests for mutations in the following genes should be ordered sequentially: VHL, RET, SDHx, TMEM127, and MAX. This particular case presented with bilateral pheochromocytoma and a RET proto-oncogene mutation, but no other neoplasms. The definite treatment is laparoscopic adrenalectomy by an experienced endocrine surgeon with preoperative alpha-adrenergic blockade. Because of the identification of the RET proto-oncogene mutation a prophylactic thyroidectomy is recommended.