Böbreğin Berrak Hücreli Sarkomu: Oldukça Nadir Bir Olgu Sunumu

Abstract

Clear cell sarcoma of the kidney (CCSK) is one of the most common malignant renal neoplasms in childhood, although it is quite rare. Its incidence peaks around the age of 3 and it is twice as common in males. We present a rare case of CCSK showing a rare histopathological pattern in terms of age and gender. A 7-month-old female patient presented with complaints of vomiting, abdominal swelling, and diarrhea. Imaging analysis revealed a mass in the right kidney, and right radical nephrectomy was performed, considering Wilms tumor (WT). There was a solid gray-white mass that completely filled the kidney, with a maximum dimension of 8.5 cm, macroscopically. The samples obtained showed intratubular structures within the tumor and kidney parenchyma in limited areas at the periphery. The tumor had a normochromic monotonous nucleus with occasional clear cytoplasm and mostly exhibited a palisade-like arrangement pattern. In the differential diagnosis, with blastemal WT and Ewing sarcoma being the primary considerations, the positivity of CyclinD1 markers, negativity of other markers, and morphological characteristics were evaluated in favor of CCSK with a palisaded Schwannian pattern. The patient was put on an intensive chemotherapy process, but was lost after relaps at weet 24. CCSK is seen in a similar age group as WT but is distinguished by its rarity and relatively worse prognosis. Histopathologically, it most commonly presents in a myxoid pattern and least commonly in anaplastic pattern. The palisaded schwannian type seen in our case is recorded at a rate of 11%. No spesific diagnostic marker has been identified immunohistochemically, but the overexpression of markers such as CyclinD1, BCOR, and EZH2 is reported to be helpful in diagnosis. Due to its high metastatic potential and limited treatment options, further research is needed to understand the molecular nature of the disease.