Ewing sarcoma family of tumors: a model for the new era of integrated laboratory diagnostics.

The Ewing sarcoma family of tumors (ESFT) represents one of the best models illustrating the multifaceted approach to the diagnosis of cancer that has evolved over the past decade. ESFT encompasses tumors that arise in bone or soft tissues and may have disparate histologic features. As a result, it was not until the discovery that these tumors share a common underlying molecular pathogenesis (chromosomal translocations involving the EWS gene and one of several members of the ETS family of transcription factors) that significant advances in the diagnosis and therapy of ESFT became possible. As a result, ESFT has come to embody the amalgamation of classical diagnostic tools, such as histology and routine microscopy, with newer techniques, such as immunohistochemistry and molecular techniques; the latter include PCR-based methods and fluorescence in situ hybridization. This review will address the features of ESFT and how it has emerged as a model for the new era of integrated diagnostics.