Rhabdoid tumor of the kidney: a report of two cases with respective tumor markers and a specific chromosomal abnormality, del(11p13).

Malignant rhabdoid tumor is a rare, aggressive, invariably lethal tumor that is resistant to multimodal treatment. In this report, two patients with malignant rhabdoid tumor of the kidney (RTK) are described. The first patient is the first case of RKT with hyperreninemia, and the second case is also the first case with a specific chromosomal abnormality, del 11p13. The first patient presented with hematuria and a mass in the left kidney. Plasma renin, angiotensin, and aldosterone levels were elevated and paralleled the tumor progression. The karyotype of the tumor cells was normal (46,XX). In the second patient, who presented with a mass in the right kidney, the concentration of plasma tissue polypeptide antigen was elevated and paralleled the tumor progression. The karyotype of the tumor cells was 46,XX, del(11)(pter-p13::p12-qter). RTK with a cytogenetic abnormality of del(11p13), which is usually found in aniridia-Wilms' tumor syndrome, has not been known. Both patients died of metastatic disease within 7 months of diagnosis in spite of the multimodal therapy. The clinicopathology of RTK and the differences between Wilms' tumor and RTK raise compelling questions which should be the subject of future studies.