Cytogenical analysis of brain tumors by FISH (fluorescence in situ hybridization) and FCM (flow cytometry).

In the present study, an analysis was made of chromosomal aberrations in brain tumors using the fluorescence in situ hybridization (FISH) technique. At the same time DNA histograms were obtained by flow cytometry (FCM) to make a comparative study of histological malignancy and prognosis. The subjects included 30 gliomas (7 of astrocytoma grade II, 15 of anaplastic astrocytoma (grade III), 8 of glioblastoma (grade IV)) and 26 meningiomas. In the study of FISH, DNA probes for chromosomes No. 7, 9, 10, and 17, were used to cause a reaction with chromosome No. 22 added for meningiomas. In the study with FCM, DNA index from DNA histogram was calculated using lymphocytes as the internal standard. In gliomas as a whole, chromosomes No. 7 and 17 showed high values, whereas, chromosomes No. 9 and 10 low values. Analysis by the grades of glioma showed that compared with gliomas of other grades, grade IV gliomas were higher for chromosome No. 17 and lower for chromosome No. 10. In meningiomas, while many cases showed a low value for chromosome No. 22, most cases of recurrent and atypical meningiomas showed a high value for chromosome No. 17. In gliomas, DNA index showed a correlation with the grade, and a positive correlation particularly with chromosome No. 17 in FISH. Recurrent and atypical meningiomas had a high DNA index.