Primary Ewing sarcoma/primitive neuroectodermal tumor in the adrenal gland

Primary Ewing sarcoma or primitive neuroectodermal tumor (PNET) of the adrenal gland is extremely rare. We report a case of Ewing sarcoma or PNET of the adrenal in a 48-year-old Chinese woman. The patient was hospitalized with left upper quadrant abdominal pain and swelling that had been present for 1 year. Computed tomography (CT) images revealed a circumscribed mass in the left adrenal region measuring 12 cm in its greatest dimension, and the mass was surgically resected. Macroscopically, the mass (13 × 10 × 8 cm³) in the left adrenal gland was encapsulated, soft, appearing grayish white and yellow, and with foci of cystic degeneration, necrosis, and hemorrhage on cross-sectional. Non-tumorous adrenal tissue was compressed, but identifiable at the periphery of the specimen. Histologically, compact short spindle and oval tumor cells were arranged in sheets. Tumor cells tested positive for vimentin, CD99, Bcl-2, NKX2.2, EMA, and CD117, and weakly positive for FLI-1 on immunohistochemical analysis and showed rearrangement of the EWSR1 on fluorescence in situ hybridization analysis. Post-adrenalectomy, after being recurrence free for 4.5 years, the patient relapsed and a localized recurrence was detected on a follow-up CT scan.