MON-388 To Cut Or Not To Cut? Cystic Adrenal Lymphangioma Mimicking Pheochromocytoma.

Background:Lymphangiomas are rare benign vascular tumors. Adrenal gland lymphangiomas are an even less common occurrence. Although usually non-functional, these tumors may mimic pheochromocytomas [1]. We present a case of a patient with a cystic adrenal lymphangioma with elevated catecholamines in the setting of acute appendicitis. Case presentation:A 30 year-old-man with a history of intermittent anxiety presented with abdominal pain. An abdominal computer tomography (CT) scan, physical examination, and laboratory findings were consistent with acute appendicitis. The patient was incidentally found to have a well-demarcated 3.9x4.6 cm right adrenal mass measuring 10 HU. A prior CT scan of the abdomen performed four years earlier showed a 2.5x3.2 cm right adrenal mass. Hormonal evaluation had not been conducted at that time.Further evaluation during the hospitalization revealed normal electrolytes, dehydroepiandrosterone, overnight dexamethasone suppression test, aldosterone/renin ratio and plasma catecholamines. However, 24-hour urine catecholamines and metanephrines were elevated: epinephrine - 63 mcg/24hr (n<21), norepinephrine - 106 mcg/24hr (n 15-80) and dopamine - 540 mcg/24hr (n 65-400). Due to the size of the lesion (>4 cm), surgical resection was recommended. Due to concern that abnormal urinary values could indicate pheochromocytoma, the surgery was preceded by 14 days of alpha-adrenergic blockade. The patient underwent a successful laparoscopic right adrenalectomy with concomitant interval appendectomy. Final pathology results revealed a cystic lymphangioma of the right adrenal gland with positive D2-40 and CD-31 immunohistochemical stains supporting this diagnosis. During follow-up evaluation, the patient reported interval resolution of intermittent anxiety and urine catecholamines/metanephrines gradually normalized. While not confirmatory of a catecholamine secreting adrenal lymphangioma, interval resolution of the anxiety disorder could suggest this diagnosis as a possibility to consider. Conclusion:The rare nature of adrenal lymphangiomas has led to a paucity of information regarding their detection and management [2]. Although typically considered benign, there are no methods at our disposal to confirm this diagnosis without surgical removal. Adrenal lymphangiomas mimicking other adrenal masses, including pheochromocytoma, have been reported [2]. Increasing the awareness regarding these rare tumors may enable providers to be on the lookout for adrenal lymphangiomas when evaluating patients for large unilateral adrenal lesions. References:1. Hodish I, Schmidt L, Moraitis AG. Adrenal Lymphangioma Masquerading as a Catecholamine Producing Tumor. Case Rep Endocrinol. 2015;2015:380151.2. Michalopoulos N, Laskou S, Karayannopoulou G, et al. Adrenal Gland Lymphangiomas. Indian J Surg. 2015; 77:S1334-S1342.