Primary atypical teratoid/rhabdoid tumor of the clival region. Case report.

An atypical teratoid/rhabdoid tumor of the central nervous system (CNS) is a rare, aggressive neoplasm found in infants and children that has similar characteristics to CNS primitive neuroectodermal tumors/medulloblastomas. The authors present the case of a patient with an atypical teratoid/rhabdoid tumor and discuss the imaging, histopathological, immunohistochemical, and cytogenetic findings. Tumor cells displayed positive reactions for vimentin, epithelial membrane antigen, and cytokeratin, and they displayed no reaction for glial fibrillary acidic protein, desmin, and actin. The karyotype was 46, XY. The phenotype of an atypical teratoid/rhabdoid tumor appears heterogeneous when examined by histological, immunohistochemical, and genetic analysis. The authors describe the case of a 4-year-old boy who harbored an atypical teratoid/rhabdoid tumor in the clivus, which appeared as a chordoma on neuroimages. To their knowledge, this location of an atypical teratoid/rhabdoid tumor has not been described in the literature.