Primary Ewing's sarcoma/primitive neuroectodermal tumor of kidney: A rare case report

Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) is a member of small round cell “blue tumor” family, occurring primarily in kidney is quite rare. Hence, detail appraisal is needed using histopathology, immunohistochemistry, and cytogenetic studies to attest the final diagnosis of ES/PNET, as this has an aggressive course and poor outcome. Here, we present a case of primary ES/PNET of kidney in 22-year-old male with locally invasive disease. Tumor cells were strongly positive for CD99 and FLI-1 on immunohistochemistry, thus confirming the final diagnosis.