Establishment and characterization of malignant rhabdoid tumor of the kidney

Malignant rhabdoid tumor of the kidney (MRTK) is a highly aggressive tumor which occurs in childhood and which is histologically characterized by the existence of eosinophilic intracytoplasmic inclusions. We established and c haracterized a cell line from this tumor with histological, immunohistochem ical and cytogenetical analysis. Histologically, the tumor cells demonstrat e typical eosinophilic inclusions, while immunohistochemically the cells de monstrate common mesenchymal and epithelial differentiation. Although the c onventional karyotyping of this tumor lacked the abnormalities of 22q chrom osome, Southern blot analysis and microsatellite analysis verified abnormal ities of the BCR gene and of the hSNF5/INI1 gene. Despite the variety of lo cations, these common genetic abnormalities appear to contribute to disting uish rhabdoid tumor from such other small round cell tumors as primitive ne uroectodermal tumor, rhabdomyosarcoma, poorly differentiated synovial sarco ma and desmoplastic small round cell tumor.