Too Young for Clear Cell Sarcoma of the Kidney? A Case Report With Review of Differential Considerations

Abstract Clear cell sarcoma of the kidney (CCSK) comprises 3% of all childhood renal cancers. Accurate diagnosis is vital for appropriate therapy, which results in a 70% to 90% overall survival rate in this previously lethal tumor. Renowned for its ability to mimic and be mimicked by every other pediatric renal tumor, and even some extrarenal retroperitoneal tumors, CCSK has a unique metastatic pattern and molecular aberrations, as well as a generally consistent clinical presentation which is of great utility in the differential. A case of CCSK in a 4-month-old boy is presented, only the fifth case reported in a patient younger than 6 months.