MALIGNANT RHABDOID TUMOR OF THE COLON - REPORT OF A CASE WITH MOLECULAR ANALYSIS

PURPOSE: Malignant rhabdoid rumors were first described in the kidney as a rare variant of Wilms' tumor with a ''rhabdomyosarcomatoid'' patt ern and a particularly poor prognosis. Further studies have demonstrat ed these neoplasms as a distinct clinicopathologic entity. Subsequentl y, tumors with a similar histologic appearance, demonstrating the ''rh abdoid'' cells, have been found in a variety of extrarenal sites. METH ODS: We report here a case of malignant rhabdoid tumor of the colon st udied with selected molecular techniques. RESULTS AND CONCLUSIONS: Thi s tumor demonstrated several unusual findings for malignant rhabdoid t umors of renal or extrarenal sites, including aneuploidy by flow cytom etric analysis and a positive nuclear immunohistochemical staining for p53 protein, which suggests presence of p53 gene mutation. DNA analys es, however, failed to demonstrate the presence of point mutation in a ny of the ras family genes.