MON-LB065 A Norepinephrine-Only Secreting Pheochromocytoma in the Absence of an Identifiable Genetic Defect

Abstract

Listen

Translate article

Introduction - Pheochromocytoma is a rare catecholamine-secreting tumor with an incidence as low as 0.8 per 100,000 individuals. Despite the rarity of pheochromocytoma, the availability of definitive treatment makes early diagnosis crucial to avoid life-threatening hypertension. The objective of this report is to describe a case of norepinephrine-only-secreting pheochromocytoma. Case Description - A 33-year-old female with a medical history of hypertension presented with complaints of acute, left-sided chest pain and palpitation. She also reported intermittent dizziness and headache for previous one week. Vital signs pertinent for blood pressure 160/80mmHg and physical exam was unremarkable. Initial evaluation with chest radiograph showed an 8.8x8.3cm peripherally calcified mass in the left upper quadrant. Subsequent computed tomography of the abdomen revealed a 10cm heterogeneous left adrenal mass, size concerning for malignancy, with central necrosis and calcification. Hormonal workup for adrenal mass resulted with normal serum testosterone, DHEA-S, morning cortisol, ACTH, aldosterone, plasma epinephrine, and dopamine levels, but profoundly elevated plasma norepinephrine 4124 (80-520) pg/mL. Her 24-hour urinary metanephrine levels were normal but with elevated normetanephrine 24,364 (88-444) ug/24hr, confirming a pheochromocytoma. The normal metanephrine level in the setting of profoundly elevated normetanephrine raised concern for Von Hippel Lindau (VHL). Ultrasound-neck showed benign, bilateral cystic nodules and her thyroid function tests, serum calcitonin were unremarkable. Oncologic workup showed confinement of tumor to the left adrenal. She was started on high salt and high fluid diet. After adequate alpha blockage, the beta-blocking drug was initiated and she underwent robotic laparoscopic removal of the left adrenal gland. The surgical pathology report confirmed benign, 9.8cm pheochromocytoma confined to left adrenal. She was started on corticosteroid postoperatively given relative adrenal insufficiency, but with anticipation of eventual steroid wean. The patient had complete resolution of symptoms and remains clinically stable. Conclusion - Pheochromocytomas arise from chromaffin cells of the adrenal medulla. Although commonly sporadic in nature, a myriad of familial syndromes are associated with pheochromocytoma. The characteristic feature of VHL-associated pheochromocytoma is almost exclusive secretion of normetanephrine and high normetanephrine to metanephrine ratio as seen in this case. Gene testing and confirmation helps with appropriate surveillance and follow up. This case is unique due to the benign pathology despite the large size and negative paraganglioma-pheochromocytoma genetic panel, despite the presence of characteristic features of VHL-associated pheochromocytoma. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.