✓The authors describe the case of a patient with a glioblastoma multiforme who showed remarkably good response to chemotherapy. A genetic analysis using comparative genomic hybridization (CGH) revealed that the tumor had a gain on the q arm of chromosome 1 (1q). Using CGH for a series of genetic analyses of more than 180 patients with gliomas, six were found to have a demonstrated 1q gain. Although the tumors in all six of these cases were histopathologically diagnosed as high-grade gliomas, compared with other malignant gliomas they demonstrated a good prognosis because of their favorable chemotherapeutic sensitivity. In immunohistochemical tests, most of the tumor cells in these cases were negative for O6-methylguanine–DNA methyltransferase, which antagonizes the effect of DNA-alkylating chemotherapeutic agents. The authors believed that a gain of 1q could be produced through the genetic events that cause loss of 1p, because these chromosomal aberrations have an imbalance of DNA copy number in common (1p <1q). A gain of 1q is an infrequent chromosomal aberration and its clinical importance should be investigated in a larger study; however, patients with malignant gliomas demonstrating a 1q gain possibly show longer survival and good response to chemotherapy similar to patients with tumors demonstrating 1p loss. The importance of using genetic analysis for gliomas is emphasized in this report because it may help in selecting cases responsive to chemotherapy and because appropriate treatment for these patients will lead to progress in the treatment of malignant gliomas.
Satoshi Takahashi, Yuichi Hirose, Eiji Ikeda, Raita Fukaya and Takeshi Kawase
Shigeo Ohba, Kazunari Yoshida, Yuichi Hirose, Eiji Ikeda, Yoichi Nakazato and Takeshi Kawase
This 32-year-old woman, 27 weeks pregnant, harbored a cystic mass with a solid component in the left frontal lobe. Histologically, the lesion was hypercellular and contained a diffuse sheet of eosinophilic cells of various sizes. The cells were almost round and had a few prominent, eccentrically placed, hyperchromatic nuclei of various sizes. Immunohistochemically, the tumor was reactive for vimentin, epithelial membrane antigen, cytokeratin AE1/AE3, smooth muscle actin, and BAF47/INI-1, and negative for glial fibrillary acidic protein, neurofilament protein, S100 protein, CK7, CK20, HMB-45, MIC2, and Bcl-2. The Ki 67 labeling index was 4.2%. Comparative genomic hybridization analysis revealed aberrations of the chromosomal copy number of +7 and −10. This tumor could not be categorized according to the present World Health Organization classification. Results of staining with glial fibrillary acidic protein were not consistent with a glioma, and staining with INI-1 was inconsistent with atypical teratoid/rhabdoid tumor. The tumor was therefore designated as a “cerebral tumor with extensive rhabdoid features.”