Endocrine Abstracts

Introduction: Giant and cystic catecholamine-secreting tumors are usually asymptomatic and detected incidentally during imaging. A simple mobilization of the tumor can cause the release of catecholamines into the blood and is therefore associated with high morbidity and mortality. Here, we aimed to present a patient with a 13 cm mass in the left adrenal gland and diagnosed as giant cystic pheochromocytoma.

Case Report: A 62-year-old male patient presented with left flank pain and frequent urination for 6 months. Abdominal computerized tomography (CT) showed a 133*78 mm non-adenoma mass with a density of 50 HU (Hansfield Unit) and containing cystic-solid areas in the left adrenal gland. There were no symptoms or signs suggestive of pheochromocytoma such as headache, palpitation, flushing, excessive sweating and chest pain. He had type 2 diabetes and coronary artery disease for 7 years, but he did not have hypertension. On examination, blood pressure and pulse measurements were normal. Ambulatory blood pressure measurements were also normal. In laboratory results, plasma metanephrine level was 975.66 pg/ml (<90) and normetanephrine was 1204.42 pg/ml (<180), urine metanephrine was 4162.77 µg/24 h(50-250) and normetanephrine was 6170.14 µg/24 h (100-500). Hyperaldosteronism and Cushing’s screening tests were normal. F-18 FDG PET/CT was performed to rule out malignant pheochromocytoma, no metastasis was detected. Adequate alpha blockade was achieved with doxazosin and left adrenalectomy was performed by an experienced surgical team. No perioperative blood pressure fluctuation was observed. On pathological examination, tumor size was 13.5*8.9*8.7 cm and weight was 274 grams. Macroscopically, it was a well-circumscribed brown mass containing cystic areas with multiple septations. In microscopic examination, there was no atypical mitotic activity, no significant pleomorphism and no increase in cellularity. There was no extraadrenal and vascular invasion, but capsule invasion was present. In the immunohistochemical examination, there was staining with chromogranin A and synaptophysin, and the ki-67 index was <1%. The diagnosis of pheochromocytoma was confirmed, and he was followed closely due to the large size of the tumor and capsule invasion.

Conclusion: Giant cystic pheochromocytoma is a rare entity and is mostly asymptomatic. Pheochromocytoma should be considered in the differential diagnosis of retroperitoneal tumors in patients with nonspecific symptoms and adequate therapy should be given to increase perioperative safety. It should be noted that the only curative treatment of such tumors is surgical resection.