Malignant rhabdoid tumors of the CNS

Abstract

Rhabdoid tumors are a group of rare and highly aggressive neoplasms occurring at almost any anatomical location and presenting predominantly in early childhood [15]. Malignant rhabdoid tumors (MRT) were first described in the kidney and were thought to represent a sarcomatous variant of Wilms' tumor [3]. Similar tumors were subsequently identified at numerous extra-renal locations, including the CNS, which remains the most frequent extra renal location [18]. Although CNS MRT is now well recognized as a defined entity, there have historically been difficulties in making the diagnosis. The tumor may be largely composed of rhabdoid cells, but may also contain mesenchymal and epithelial elements (termed atypical teratoid/rhabdoid tumors, AT/RT). Furthermore 70% of CNS malignant rhabdoid tumors contain fields of cells indistinguishable from primitive neuroectodermal tumor/medulloblastoma (PNET MB) [4]. Adding to the confusion is the fact that these two entities also share clinical and radiological features [27]. Only 10-15% of CNS MRTs consist almost exclusively of rhabdoid cells. They exhibit a broad range of immunohistochemical reactions corresponding to differing tissue subtypes [13]. © 2010 Springer-Verlag Berlin Heidelberg.