Primary primitive neuroectodermal tumor of the kidney

Abstract

Renal primitive neuroectodermal tumor (PNET) is a rare entity. It should be differentiated from other primary renal malignancies. The differentiation of the malignant small round cell tumors may be challenging; however, it is essential for better management of the patient. We report a 45-year-old male having complaints of pain in the abdomen, hematuria, and mass in the abdomen for 6 months. Abdominal and pelvic sonography finding showed cystic-solid, right renal mass suggestive of malignancy. On histopathology diagnosed as malignant small round blue cell tumor suggestive of primitive neuroectodermal tumor. On immunohistochemistry, CD99 positivity confirmed the diagnosis of primary PNET of the kidney. We are presenting this case for its rarity, clinical presentation, and pathological findings.

Renal Primitive Neuroectodermal Tumor or Renal Ewing Sarcoma

“…Application of immunohistochemistry helps in differentiating from other small round cell tumor of kidney like nephroblastoma, neuroblastoma and desmoplastic small round cell tumor. 2,11,12 Our case showed diffuse and strong positivity of CD-99. The expression of WT-1, CD-3 and CD-20 were negative in these tumor cells.…”

“…Molecular genetic study also help in the confirmation of the diagnosis. [10][11][12][13] In this case, the histomorphological findings revealed some atypical small dark round cells arranged in clusters, nests, rosettes as well as pseudorosettes. Immunohistochemical expression of CD-99 in the cell membrane is universal in renal PNET.…”

“…The differential diagnosis includes other round cell tumors of kidney including Wilms tumor/ nephroblastoma, neuroblastoma, renal cell carcinoma, malignant lymphoma, desmoplastic small round cell tumor, clear cell sarcoma, synovial sarcoma and metastatic small round cell tumor from other site. 11,12 This differential diagnosis is further complicated by the overlapping morphological features and the relatively rare occurrence of most of these entities in the kidney. 10 Reportedly, renal PNET usually occur in young adults with a mean age of 30.5 years having 66.7% male predominance.…”

Undiagnosed polycythemia, an uncommon cause of Wallenberg syndrome: A case report

“…Renal diseases are also closely associated with secondary polycythemia. Diseases including primitive neuroectodermal tumor (PNET), nephroblastoma, carcinoid, and neuroblastoma need to be ruled out 20 . In order to evaluate the presence of any renal etiology, urinalysis, renal function tests, renal ultrasound, and CT scan are required 21 …”

“…Diseases including primitive neuroectodermal tumor (PNET), nephroblastoma, carcinoid, and neuroblastoma need to be ruled out. 20 In order to evaluate the presence of any renal etiology, urinalysis, renal function tests, renal ultrasound, and CT scan are required. 21 Management of acute ischemic stroke in polycythemia is also unique; it is the only situation where the American Heart Association stroke guidelines suggest a possible value of haemodilution.…”