Metastatic Ewing sarcoma masquerading as olfactory neuroblastoma.

Ewing sarcoma is a malignant tumor of bone that rarely spreads to the head and neck. We describe an unusual case of metastatic Ewing sarcoma involving the calvarium mimicking olfactory neuroblastoma, an uncommon neuroectodermal tumor of the anterior skull base. Pertinent clinical, radiological, and pathologic features of these tumors are described, with particular attention to their imaging characteristics.