Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor

**Semantic type:** Neoplastic Process

**Definition:** The reemergence of a malignant small round cell tumor with or without neural differentiation after a period of remission.

**Synonyms:** - Recurrent Ewing's Sarcoma/Peripheral Primitive Neuroectodermal Tumor - Recurrent Tumors of Ewing's Family - Recurrent Tumors of the Ewing's Family