PRIMARY MALIGNANT RHABDOID TUMOR OF THE SPINAL DURA

We report a case of an intradural extramedullary malignant rhabdoid tu mor (MRT) occurring in a 2-year-old girl. Histologically, immunohistoc hemically and ultrastructurally, the tumor fulfilled the diagnostic cr iteria for MRT. Many tumor cells contained typical cytoplasmic eosinop hilic hyaline inclusions which were filamentous by electron microscopy . Positive vimentin staining was observed immunohistochemically but ep ithelial markers were negative. Extrarenal MRT are rare. Ten instances in the central nervous system have been reported. This case is the fi rst intradural MRT of the spinal canal. The differential diagnosis fro m other tumors of this region is important because the prognosis and t herapeutic approaches are greatly different.