Primitive Neuroectodermal Tumor of the Kidney

Primitive neuroectodermal tumor (pnet) is an uncommon malignancy of bone and soft tissuewitch rarely occurs in the kidney. in more than 90% of the cases, the tumor cells relieves abalanced translocation (11; 22) (q24; q12). immunohistochemical staining may be required fordiagnosis of pnet. the cells of tumor express cd99, vimentin, nse, fl1 but do not express ck,lca, myogenin, and wt1. we present a 36-year –old female with left –side tender abdominalswelling, and history of trauma to abdominal. ct imaging confirmed a huge solid mass of kidney,also extending into renal pelvis. histological section of the lesion showed a malignant proliferationof small round cells in rosette-like pattern with foci of necrosis area. tumor cells expressed highlevel of cd 99 antigen. the diagnosis of the lesion was primitive neuroectodermal tumors (pnet).following-up after 6 months showed no recurrence.