Primitive Neuroectodermal Tumor of the Kidney

Primitive neuroectodermal tumor (PNET) is an uncommon malignancy of bone and soft tissue witch rarely occurs in the kidney. In more than 90% of the cases, the tumor cells relieves a balanced translocation (11; 22) (q24; q12). Immunohistochemical staining may be required for diagnosis 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 abdominal swelling, 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 proliferation of small round cells in rosette-like pattern with foci of necrosis area. Tumor cells expressed high level of CD 99 antigen. The diagnosis of the lesion was primitive neuroectodermal tumors (PNET). Following-up after 6 months showed no recurrence.