RHABDOID TUMORS OF THE KIDNEY IN CHILDREN - CT FINDINGS

OBJECTIVE. The purpose of this study was to identify CT characteristic s of rhabdoid tumor of the kidney, a rare, aggressive, malignant neopl asm of unknown origin that occurs mainly in infants and young children . MATERIALS AND METHODS. CT scans of eight children (newborn to 13 yea rs old; mode, 4 months old; six boys and two girls) with histopatholog ic diagnosis of rhabdoid tumor of the kidney were evaluated retrospect ively by two of the authors, who were not blinded to the diagnosis. Al l eight CT scans were performed with intravenous and oral contrast, an d noncontrast intravenous CT scans were available in four cases. The f ollowing CT characteristics were evaluated: location of tumor within t he kidney; presence of calcification, subcapsular hematoma, multiple t umor lobules, enlarged vessels, vascular invasion, or central tumor ne crosis or hemorrhage; visibility of tumor margin; distant metastasis; and primary tumor size. RESULTS. Air eight primary tumors (five on the left, one of which had contralateral renal nodules) were central in l ocation and involved the hilum. Calcification outlining the tumor lobu le was present in two of the four tumors on noncontrast CT scans, Subc apsular hematoma was seen in five children, Tumor necrosis and hemorrh age were seen in seven children. Tumors were well defined from the ren al cortex in four children, Lobules of tumor were seen in seven childr en. CONCLUSION. CT findings of calcification, subcapsular hematoma, an d lobular appearance in a large, centrally located, and heterogeneous renal mass in a child suggest a rhabdoid tumor of the kidney.