Brain metastases with unusual MRI features in an infant with relapsed clear cell sarcoma of the kidney: A case report.

Clear cell sarcoma of the kidney (CCSK) is a rare primary renal tumor in children. It is known for its propensity to metastasize to bones and lungs at initial diagnosis. Distant metastatic relapses occur in about 15-16% of the patients, with the brain being the most frequent site of relapse. Imaging features of brain metastases from CCSK have only been reported in a few cases and most reports lack a detailed description of the imaging findings. We present brain magnetic resonance imaging (MRI) findings in an infant with relapsed CCSK who developed multiple parenchymal metastases with concentric signal alterations and no tumor-associated edema.