Authors : Vidya Rekha R Kamath, Teerthanath S, Rajeev T P
DOI : 10.18231/j.ijpo.2020.133
Volume : 7
Issue : 4
Year : 2020
Page No : 674-677
Background: Primitive neuroectodermal tumors (PNET) is an aggressive, rapidly progressing and metastatic tumor. It rarely arises from the kidney and has an incidence of less than 1%. These are usually mistaken for a wide variety of other small round cell tumors. Young adults and children are commonly affected and have an aggressive course. These tumors are mistaken for a wide variety of other small round cell tumors. Here is a case of a 52-year-old female, who presented with flank pain and gross hematuria. The contrast-enhanced computerized tomogram (CECT) revealed a renal mass with a tumor thrombus extending to the renal vein, inferior vena cava, and the right side of the heart. The patient underwent radical nephrectomy along with IVC thrombectomy and chemotherapy.
Materials and Methods: The sections from formalin-fixed surgical specimens were paraffin-embedded and stained with H & E stain. Immunohistochemistry (IHC) was performed.
Results: Histology revealed small round to oval cells with hyperchromatic nucleus and very scanty cytoplasm. Frequent mitotic figures were noted. Few rosettes were seen at places. Tumor was seen invading the perirenal adipose tissue. The tumor thrombus extended into the right atrium and the right ventricle.
IHC evaluation revealed the tumor cells showed a strong positivity for CD99, synaptophysin, neuronspecific enolase, vimentin, and were negative for CD45, pan-cytokeratin, and desmin. Thus, the histological examination and IHC helped in getting a definite diagnosis of PNET involving the kidney. The patient has been undergoing chemotherapy.
Conclusion: PNET has an aggressive clinical course with a poor prognosis. Renal PNET bears many similarities to other small round cell tumors; hence it is important to review the histologic features and immunostaining for definitive diagnosis. Due to the rarity of the disease, there is no standard guideline regarding its management. Achieving accurate diagnosis facilitates the prolongation of survival with definitive treatment.
Keywords: Kidney, Immunohistochemistry, Primitive neuroectodermal tumor.