Clinicopathologic Findings of Atypical Teratoid/Rhabdoid Tumor of the Central Nervous System.

Park, Seung Kyu; Lee, Min Cheol; Jung, Shin; Kim, Yong Su; Lim, Jun Seob; Cho, Kyu Yong

Original Article

Journal of Korean Neurosurgical Society 2003;33(1): 44-50.

Seung Kyu Park, Min Cheol Lee, Shin Jung, Yong Su Kim, Jun Seob Lim, Kyu Yong Cho

¹Department of Neurosurgery, Gwangju Christian Hospital, Gwangju, Korea. skparkjm@hanmail.net
²Department of Pathology, Chonnam National University Medical School, Koera.
³Department of Neurosurgery, Chonnam National University Medical School, Koera.
⁴Research Institute of Medical Sciences, Gwangju, Korea.

ABSTRACT

OBJECTIVE
Atypical teratoid/rhabdoid tumor(AT/RT) is a new entity among malignant pediatric brain tumors, and shows variable histopathologic features. The authors investigate the clinicopathologic and cytogenetic features of the tumor.
METHODS
Five cases were included in this study ; three of them were primarily diagnosed, and two cases were reclassified from primitive neuroectodermal tumor/medulloblastoma to AT/RT. Mean age of patients at diagnosis was 5.6 years. The tumors were located in infratentorial or supratentorial areas. Maximum survival period was 13 months. RESULTS: Histopathologically, the tumors were mainly composed of modified rhabdoid cells and undifferentiated small cells, and mixed with epithelial, mesenchymal components, and other features mimicking glioma and chordoma. The histopathologic features were supported by polyphenotypic immunoreactivity, including epithelial membrane antigen, cytokeratin, vimentin, smooth muscle actin, and glial fibrillary acidic protein. Cytogenetic studies for karyotype analysis and fluorescent in situ hybridization revealed monosomy of chromosome 22 in two cases out of three cases of the tumor. CONCLUSION: Atypical teratoid/rhabdoid tumor may be an unique clinicopathologic entity, and histopathologic diagnosis should be made carefully by differentiating other polymorphous tumors of the brain.

Key Words: Atypical teratoid/rhabdoid tumor; Histopathology; Cytogenetics