Primary Ewing's sarcoma/primitive neuroectodermal tumor of the kidney: Report of a case diagnosed by fine needle aspiration cytology and confirmed by immunocytochemistry and RT‐PCR along with review of literature

Abstract

Primary Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) of the kidney is a distinct entity that can be mistaken for variety of round cell tumors. We report a rare case of ES/PNET of the kidney in a 35-year-old female patient diagnosed by fine needle aspiration cytology (FNAC) and confirmed by immunohistochemistry (IHC) and reverse-transcriptase polymerase chain reaction (RT-PCR). Ultrasound guided FNAC smears from the kidney mass showed a population of malignant small round cells with perivascular arrangement and focal rosette formation. IHC performed on the cell block, showed strong immunopositivity for CD99 (MIC2) and vimentin. Molecular analysis of the aspirate by RT-PCR confirmed the EWS-FLI type1 transcript. The application of RT-PCR on FNAC material for establishing a diagnosis of renal ES/PNET is being reported for the first time. FNAC also confirmed metastases in the right level I cervical lymph node. The utility of IHC and molecular techniques in diagnosis of such a rare case is stressed and relevant literature is discussed.

Primitive neuroectodermal tumor of the kidney at the advanced stage: A case series of eight Chinese patients

“…WT-1, a common marker for Wilms' tumor, has been used to rule out the diagnosis of PNET, while rPNETs may stain positive for WT-1. A cytogenetic study performed to detect the EWS/FLI-1 fusion gene revealed a translocation of chromosomes 11 and 22, t(11:22) (q24:q12), in >90% of rPNET cases (18), while the use of FISH for the detection of the fusion gene may increase the specificity of this marker and decrease false-positive test results. In the present study, FISH detection was performed for one case, also revealing t(11;22)(q24;q12) translocation.…”

Metachronous renal Ewing sarcoma/primitive neuroectodermal tumour in a survivor of Burkitt lymphoma

“…Histologically, it can be challenging to differentiate renal ES from other SRBCTs, synovial sarcoma, malignant lymphoma, WT, neuroblastoma and small cell neuroendocrine tumour because these tumours often show overlapping cytomorphological features 13. Therefore, immunocytochemistry and detection of the translocation by FISH or RT-PCR techniques have always been critical in reaching the diagnosis.…”

Primitive neuroectodermal tumor of the kidney: case report and review of literature

“…The translocation of t(11:22) (q24:q12) with the fusion transcript between the EWS gene (22q12) and the ETS-related oncogene (11q24) have been detected in more than 90% of the rPNET [5]. Several studies applied preoperative fine needle aspiration cytology to diagnose rPNET based on the constellation of cytomorphologic and immunohistochemical findings with subsequent confirmation by cytogenetic analyses [11-13]. …”