Abstract
Extraskeletal Ewing's Sarcoma/Primitive Neuroectodermal Tumor presenting as a breast mass is uncommon. It may pose a diagnostic challenge. In order to increase awareness and identify potential diagnostic pitfalls, we report a 24 year-old woman extraosseous Extraskeletal Ewing's Sarcoma/Primitive Neuroectodermal Tumor arising in the breast.