Document Type: Case Reports
Dept of Pathology, Mashhad University of Medical Sciences, Mashhad, Iran
Dept. of Urology, Mashhad University of Medical Sciences, Mashhad, Iran
Oral and Maxillofacial Diseases Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
Primitive neuroectodermal tumor (PENETs) 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 PENET. 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.