Disseminated Intracranial Ewing's Sarcoma in an Adult: A Rare and Difficult Diagnosis.

The Ewing sarcoma family of tumors comprises a rare class of cancers of mesenchymal origin. Cases of Ewing's sarcoma in the central nervous system - specifically, intracranial Ewing's - are extremely rare. Almost all reported cases have occurred in children. However, this rare presentation can also occur in the adult population. It is important to distinguish these tumors from primitive neuroectodermal tumors at the time of diagnosis. Testing for EWSR1(22q12) gene rearrangement using fluorescence in situ hybridization is a useful tool for making the distinction between these 2 similar but distinct entities. We present here the case of a middle-aged male patient with intracranial Ewing's sarcoma, and discuss diagnostic challenges and potential new treatment approaches for this rare disease.