Ewing Sarcoma and Primitive Neuroectodermal Tumor of the Esophagus: Report of a Case and Review of Literature

This study presents a case of Ewing sarcoma and primitive neuroectodermal tumor arising in the esophagus of a 44-year-old woman who presented with progressive dysphagia. Imaging studies demonstrated a polypoid lesion in the esophagus. The tumor was characterized by corded and pseudopapillary architecture, cytologic monotony, and low proliferative activity. Immunohistochemical stains were positive for CD99, neuron-specific enolase, vimentin, cyclin D1, p53, and FLI1 gene product. Fluorescence in situ hybridization demonstrated a 22q12 translocation, associated with primitive neuroecto-dermal tumor in the tumor cells, whereas reverse transcription polymerase chain reaction conformed expression of Ewing sarcoma/FLI1 fusion transcript in the patient’s bone marrow aspirate. Although this is a rare site for this type of tumor to occur, primitive neuroectodermal tumor should be considered in the differential diagnosis of mesenchymal tumors of the esophagus. Genetic analysis is crucial to establish the diagnosis and can be successfully performed on formalin-fixed, paraffin-embedded material and hematopoietic tissue. Keywords esophagus, primitive neuroectodermal tumor, immunohistochemistry, fluorescence in situ hybridization The Ewing family of tumors (EFTs) comprises Ewing sarcoma (EWS) and peripheral primitive neuroectoderma