Abstract
A typical retratoid/thabdoid tumor (AT/RT) of the contral nervous system (GNS) is a recently described infantile brain turmor exhibiting unusually aggressive clinical behavior, i.e., a greater than 80% mortality at 1 year. Although often mistaken for primitive neuroectodermal tumor (PNET)/medulloblastoma because of its frequent posterior fossa location. It does not respond to standard PNET treatment protocols. Fottunatelly, its histologic features, immunophenotype, and cytologic profile are distinctive. The recognition of AT/RT is extremely important because appropriate treatment may influence the natural history of the disease.