Comments: This highly malignant renal tumor of childhood usually presents before 3 years of age. Malignant Extrarenal Rhabdoid Tumors and Composite Extrarenal Rhabdoid Tumors admixed with other phenotypes have also been recognized. Common to all these entities is the rhabdoid phenotype – consisting of a high-grade, round cell tumor with abundant cytoplasm and containing cells with cytoplasmic filamentous inclusions. Cytogenetic studies have revealed karyotypic abnormalities of 22q11-12 in many cases (Am J Surg Pathol 1999 March; 23 (3):249-56.)
