FRI230 Cystic Pheochromocytoma

Disclosure: S. Saberi: None. A 67-year-old woman presented with right abdominal tenderness, abdominal distention, gas and belching. Her blood pressure was 134/70, pulse 84 with no palpable abdominal mass. Her medical history includes depression and anxiety which developed 17 years prior and later resolved. She was diagnosed with hypertension approximately 20 years earlier initially well-controlled with candesartan-hydrochlorothiazide 16-12.5 mg daily and metoprolol succinate ER 50 mg daily. Two years prior to presentation her blood pressure rose to the 180s/90s requiring doubling of her candesartan-hydrocholorothiazide. An abdominal ultrasound was obtained which showed an abdominal mass. Subsequently, a CT of the abdomen and MRI of the abdomen with and without contrast were obtained revealing a 10 cm predominantly cystic adrenal mass with partial irregular wall thickening and nodularity causing mass effect on the inferior vena cava, liver and right kidney. Results of lab testing revealed an elevated plasma free metanephrines 1187 pg/ml (normal < 57 pg/ml), plasma free normetanephrines 1911 pg/ml (normal < 148 pg/ml), total free metanephrines and normetanephrines 3098 pg/ml (normal < 205 pg/ml). Her other adrenal biochemical evaluation was normal. She underwent open right adrenalectomy after adequate pre-operative blockade. Post-operatively her plasma free normetanephrines decreased to 0.47 nmol/L (normal < 0.90 nmol/L) and plasma free metanephrines were less than 0.20 nmol/L (normal < 0.50 nmol/L). Cystic Pheochromoctyoma: Spontaneous rupture of cystic pheochromocytoma can cause an adrenergic crisis. Cystic pheochromocytoma may develop due to hemorrhage within the lesion, necrosis and subsequent cyst formation (1). Patients may present with abdominal pain, GI symptoms or palpable masses rather than classic symptoms of pheochromocytoma (2).The differential diagnosis of cystic adrenal lesions includes lymphangiomas, pseudocysts of other surrounding structures (such as liver, pancreas, kidney, spleen, retroperitoneal and urachal and mesenteric cysts), dermoids, adrenal carcinoma, hydatid cysts of the adrenal glands (3).Small case series report the incidence of adrenal cysts in adrenal disease as 5.1% (4). A female predominance has been reported in prior studies (4). More commonly cystic adrenal lesions are unilateral and present in persons aged 30s-50s (2). Adrenal cysts are classified based on their origin as endothelial cysts derived from malformation of the lymphatic or arteriovenous systems, pseudocysts derived from prior hemorrhage, epithelial cysts with thin wall and serous fluid, or parasitic cysts. Necrosis and liquefaction in the adrenal lesion may lead to fluid accumulation and a cystic appearance. Large cysts are at risk for hemorrhage and rupture. All adrenal cysts require biochemical evaluation. Particular attention should be paid to predominantly cystic masses with any solid component as up to 7% of these may be malignant (5). Uniform guidelines for surgical management of these lesions have not been well established. Patients with symptoms such as abdominal pain, biochemical abnormalities, complications such as pressure on adjacent organs or rupture with cyst content leakage, suspicion of malignancy, cysts larger than 5 cm or increasing size of the cyst should be considered for surgical intervention (5, 6). In patients presenting with abdominal pain and hypertension who are found to have a cystic adrenal lesion pheochromocytoma should be considered. Presentation: Friday, June 16, 2023