Primary Ewing's Sarcoma/Primitive Neuroectodermal Tumor of of Kidney - a Diagnostic Dilemma.

Among the group of small round cell tumors of kidney Ewing's sarcoma/PNET is a very rare entity which has aggressive clinical course. We report a case of renal mass in 24 years old male which was histologically diagnosed as small round cell tumor of kidney. Arrangement of the malignant cell along with vascular network in a filigree pattern was suspicious for a diagnosis of Ewing's sarcoma/PNET which was confirmed by positivity of CD 99 immunohistochemically.