Clear cell sarcoma of the kidney: CT, sonographic, and pathologic correlation

Area of Science:

• Pediatric Radiology
• Pediatric Oncology

Background:

• Clear cell sarcoma of the kidney is a rare but aggressive childhood renal neoplasm.
• Distinguishing it from other renal tumors, particularly Wilms tumor, is crucial for appropriate management.

Purpose of the Study:

• To retrospectively analyze and characterize the sonographic and computed tomographic (CT) findings in children diagnosed with clear cell sarcoma of the kidney.
• To correlate imaging features with gross pathologic findings and assess their utility in differentiating this tumor from other renal neoplasms.

Main Methods:

• Retrospective review of sonographic and CT imaging in 12 children (aged 1-6 years) with pathologically confirmed clear cell sarcoma of the kidney.
• Characterization of tumor size, calcification, internal architecture, and presence of necrosis or cysts.
• Correlation of imaging findings with gross pathologic data.

Main Results:

• All 12 tumors were unilateral and large (8.5-16 cm).
• Predominantly solid masses with areas of necrosis (low attenuation/hypoechogenicity) were observed in most cases.
• Seven tumors contained uncomplicated fluid-filled cysts.
• No inferior vena cava extension was noted.
• Radiologic features were not specific and overlapped with other malignant renal neoplasms, including Wilms tumor.
• Some features mimicked benign conditions like multilocular cystic nephroma.

Conclusions:

• The imaging features of clear cell sarcoma of the kidney are not unique and overlap significantly with other malignant renal tumors in children.
• Current sonographic and CT findings do not reliably differentiate clear cell sarcoma of the kidney from Wilms tumor.
• Further research may be needed to identify specific imaging biomarkers for this rare pediatric kidney cancer.