Received: 7 September 1999 Abstract Rhabdoid tumors of the central nervous system are rare ma- lignancies with a still almost uni- formly fatal outcome. There is still no proven curative therapy available. We report our experience with nine patients with central nervous system rhabdoid tumors. Gross complete surgical removal of the tumor was achieved in six patients. Seven pa- tients received intensive chemothera- py. Four of these were treated in ad- dition with both neuroaxis radiother- apy and a local boost directed to the tumor region, while two patients re- ceived local radiotherapy only. The therapy was reasonably well tolerat- ed in most cases. Despite the aggres- sive therapy, eight of the nine pa- tients died from progressive tumor disease, and one patient died from hemorrhagic brain stem lesions of unknown etiology. The mean surviv- al time was 10 months after diagno- sis. Conventional treatment, although aggressive, cannot change the fatal prognosis of central nervous system rhabdoid tumors. As these neoplasms are so rare, a coordinated register would probably be a good idea, offering a means of learning more about the tumor’s biology and possible strategies of treatment. Key words Brain tumor · Rhabdoid tumor · Chemotherapy · Radiotherapy Child’s Nerv Syst (2000) 16:228–234 © Springer-Verlag 2000 ORIGINAL PAPER Dirk Reinhardt Julianne Behnke-Mursch Elisabeth Weiß Hans-Jürgen Christen Joachim Kühl Max Lakomek Arnulf Pekrun Rhabdoid tumors of the central nervous system Introduction Rhabdoid tumors are among the pediatric malignant tu- mors with the worst prognosis. Originally described as a variant renal tumor by Beckwith et al. [2], rhabdoid tu- mors are now histologically defined as a separate entity [14, 15]. They resemble rhabdomyosarcomas, but immu- nohistochemical and ultrastructural features allow a clear distinction between the two types of tumors [2, 15]. Rhabdoid tumors are characterized by round tumor cells with an eccentric nucleus, prominent nucleolus, vacuo- lated cytoplasm and positive immunoreactivity for vi- mentin. Often morphologic and immunohistochemical features resembling primitive neuroectodermal tumors (PNET), mesenchymal neoplasms and epithelial differ- entiation can be found simultaneously. Karyotyping has revealed a high incidence of monosomy, deletion or oth- er anomalies of the long arm of chromosome 22 [5, 16], which might lead to the loss of a tumor suppressor gene [17, 18]. Rhabdoid tumors can arise from many different organs; soft tissue seems to be the predominating origin [2, 20]. So far about 90 patients with rhabdoid tumors of the central nervous system (CNS) have been described [7, 15, 20]. The mean age at diagnosis is 2–3 years, but some adult patients have been described as well [1, 8, 11]. The sex ratio is 3:2, with boys more often affected than girls [15]. The tumors can be localized both supra- and infratentorially [7, 15]. The prognosis is still very D. Reinhardt · M. Lakomek · A. Pekrun ( ✉ ) Department of Pediatrics, University of Göttingen, Robert-Koch-Strasse 40, 37075 Göttingen, Germany Tel.: +49-551-396239 Fax: +49-551-396231 J. Behnke-Mursch Department of Neurosurgery, University of Göttingen, Göttingen, Germany E. Weiß Department of Radiotherapy, University of Göttingen, Göttingen, Germany H.-J. Christen Department of Neuropediatrics, University of Göttingen, Göttingen, Germany J. Kühl Department of Pediatrics, University of Würzburg, Würzburg, Germany