ODP307 Does Size Matter: A Case of a 16cm Pheochromocytoma

BACKGROUND: Pheochromocytomas are catecholamine producing tumors that arise from chromaffin cells. The incidence is of 0.6 cases per 100,000 person-year. Although rare, it is an unpredictable and dangerous tumor that can lead to a fatal catecholamine induced cardiovascular accident. Typical symptoms include profuse sweating, palpitations, headaches, paroxysmal hypertension, anxiety, chest pain. Occasionally, the tumor can present as an asymptomatic incidentaloma. CASE: A 55-year-old patient with no significant past medicalor family history presented to the emergency department (ED) with right lower quadrant abdominal pain. CT abdomen/pelvis demonstrated acute appendicitis and an incidental finding of a 15×10×11.8 cm left adrenal mass. The patient denied episodic headaches, palpitations, diaphoresis, chest pain, and anxiety. On exam, patient's vital signs included a blood pressure of 112/77 mmHg and pulse rate of 88 bpm. Further, there was no evidence of hypercortisolism including moon facies, acanthosis, hirsutism, abdominal striae, or proximal muscles weakness. He subsequently underwent biochemical testing which revealed 24-hour urine metanephrines of 1131 ug/d (55-320ug/d), normetanephrine of 6450 ug/g (0-330 ug/g), mildly elevated urine cortisol of 130.6 ug/d (<60 ug/d) and DHEAS of 73 ug/dL (70-130 ug/dL). In preparation for surgery, alpha blockade was initiated. He underwent successful left adrenalectomy with pathology revealing pheochromocytoma of 16 cm, focally invading the extra-adrenal adipose tissue and with a pheochromocytoma of the adrenal gland score (PASS) of 11, suggestive of high-risk disease. Biochemical testing, including a 24-hour urine and serum metanephrines, obtained approximately 6 weeks post-operatively were normal. Genetics evaluation is currently pending. CONCLUSIONS: Although pheochromocytomas are known to manifest as the classic triad of palpitations, sweating and headaches, up to 20% can be asymptomatic. Giant pheochromocytomas, defined as size greater than 10 cm, are commonly asymptomatic, hence biochemical testing should be done regardless of absence of symptoms. References: Kota S et al. Pheochromocytoma: An Uncommon Presentation of an Asymptomatic and Biochemically Silent Adrenal Incidentaloma. Malays J Med Sci. Apr-Jun 2012; 19(2): 86-91. Maharaj R, Parbhu S, Ramcharan W, et al. Giant cystic pheochromocytoma with low risk of malignancy: a case report and literature review. Case Rep Oncol Med 2017; 2017 Presentation: No date and time listed