primary ewing’s sarcoma/primitive neuroectodermal tumor of of kidney - a diagnostic dilemma

1. department of pathology, burdwan medical college, burdwan, west bengal, india 2. department of pathology, bankura sammilani medical college, bankura, west bengal, india                   corresponding author: nirmalya chakrabarti, md; tel: (+91) 9477882332 email: [email protected] received: 06 july 2014 accepted: 03 feb. 2015 iran j cancer prev. 2015; 2:129-33.     abstract 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. thus careful histological observation and immunohistochemical stains can give the proper diagnosis of primary ewing’s sarcoma/pnet thus removing the diagnostic dilemma in the group of small round cell tumors.