Ewing's Sarcoma of Sphenotemporal Bone of skull: A Rare Presentation

A 17-year-old girl presented with progressively increasing diplopia, projectile vomiting of 4-month duration with no neurological deficit. Local examination showed a hard swelling in the scalp that seemed to be arising from temporal bone. General and systemic examination was normal. MRI revealed a osseous tumor in left sphenotemporal region with solid cystic component. The patient was operated upon and excision of tumor was done. Histopathological examination showed a monomorphic small round cell tumor of bone infiltrating into the subcutaneous tissue. Immunohistochemical stain showed diffuse immunopositivity for CD 99 (MIC-2 ) in tumor cells, FISH studies showed EWS/FLI1 translocation, thus final diagnosis of Ewing’s sarcoma was made. The patient was kept for regular follow up.