Background: Ewing's sarcoma uncommonly arises from extraosseous soft tissue or parenchymal organs. Primary adrenal Ewing's Sarcoma, although very rare, is extremely aggressive and commonly fatal.

CASE PRESENTATION: A 17 year old Pakistani male was referred to the outpatient oncology clinic at our center with a three month history of concomitant pain, swelling and dragging sensation in the right hypochondrium. Abdominal examination revealed a large, firm mass in the right hypochondrium extending into the right lumbar region and epigastrium. His genital exam was unremarkable and there were no stigmata of hepatic or adrenal disease.Computed tomography scans revealed a large peripherally enhancing mass in the hepatorenal area, biopsy of which showed a neoplastic lesion composed of small round blue cells which exhibited abundance of glycogen and stained diffusely positive for CD99 (MIC2 antigen). Fluorescence in situ hybridization demonstrated gene rearrangement at chromosome 22q12 which confirmed the diagnosis of Ewing's sarcoma. Staging scans revealed pulmonary metastasis and hence he was commenced on systemic chemotherapy.

CONCLUSION: This case report highlights the importance of keeping Ewing's sarcoma in mind when a young patient presents with a large non-functional adrenal mass.