We report the 4th case of a primitive round cell sarcoma with the translocation (4;19)(q35;q13.1) as the primary cytogenetic abnormality. This undifferentiated sarcoma shows some features of Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET), including a diffuse reactivity for FLI1, but it shows only focal and weak reactivity for CD99 and is negative for a rearrangement of EWS, the molecular signature of ES/ PNET. Recognition of the histopathologic and cytogenetic features of this entity is necessary to avoid its misdiagnosis as ES/PNET, especially in small biopsy samples.
- Ewing sarcoma
- Primitive round cell sarcoma
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health
- Pathology and Forensic Medicine