AT/RT survivors; the oldest was alive at 46 months after diagnosis. (f) Medical University of Vienna, 2013, reported a 16-year survivor, among other long-term survivors Cancer treatments in long-term survivors who are children usually cause a series of negative effects on physical well-being, fertility, cognition, and learning. Metastasis Metastatic spread is noted in roughly one-third of the AT/RT cases at the time of diagnosis, and tumors can occur anywhere throughout the CNS. The ASCO study of the 188 documented AT/RT cases prior to 2004 found 30% of the cases had metastasis at diagnosis. Metastatic spread to the meninges (leptomenigeal spread sometimes referred to as sugar coating) is common both initially and with relapse. Average survival times decline with the presence of metastasis. Primary CNS tumors generally metastasize only within the CNS. One case of metastatic disease to the abdomen via ventriculoperitoneal shunt has been reported with AT/RT . Metastatic dissemination via this mechanism has been reported with other brain tumors, including germinomas, medulloblastomas, astrocytomas, glioblastomas, ependymomas, and endodermal sinus tumors. Guler and Sugita separately reported cases of lung metastasis without a shunt. Epidemiology An estimated 3% of pediatric brain tumors are AT/RTs, although this percentage may increase with better differentiation between PNET/medulloblastoma tumors and AT/RTs. As with other CNS tumors, more males are affected than females (ratio 1.6:1). The ASCO study showed a 1.4:1 male to female ratio. History Atypical teratoid/rhabdoid tumor was first described as a distinct entity in 1987. Before 1978, when rhabdoid tumor was described, AT/RT likely was misdiagnosed as medulloblastoma. In some early reports the tumor was known also as malignant rhabdoid tumor (MRT) of the CNS. Between 1978 and 1987, AT/RT was usually misdiagnosed as rhabdoid tumor. However, both AT/RT and non-CNS MRT have a worse prognosis than medulloblastoma and are resistant to the standard treatment protocols for medulloblastoma. By 1995, AT/RT had become regarded as a newly defined aggressive, biologically unique class of primarily brain and spinal tumors, usually affecting infants and young children. In January 2001, the U.S. National Cancer Institute and Office of Rare Diseases hosted a Workshop on Childhood Atypical Teratoid/Rhabdoid Tumors of the Central Nervous System. Twenty-two participants from 14 institutions came together to discuss the biology, treatments, and new strategies for these tumors. The consensus paper on the biology of the tumor was published in Clinical Research. The workshop's recognition that CNS atypical teratoid/rhabdoid tumors (AT/RT) have deletions of