Morio Matsunaga

Glioblastoma Multiforme with a Peculiar Chromosomal Aberration—Double Minute Chromosomes

The chromosomal aberration of double minute chromosomes (DMS) is a peculiar structural anomaly characterized by the occurrence of strongly varying numbers of often very small, paired chromatin bodies, in addition to the ordinary chromosomes. A glioblastoma multiforme with DMS was found in a 73-year-old female patient, who had received neither radiation nor chemotherapy before the tissue was explanted. She received computerized tomography of the brain because of severe headache, and a brain tumor was found in the right parieto-occipital lobe. The brain tumor was extirpated subtotally and the operative specimen indicated glioblastoma multiforme. In the cytogenetic study, nine cells containing DMS in this tumor tissue showed the hyperdiploid picture, with the total number of chromosomes varying from 50 to 57. Monosomy was found on chromosomes #10, 12, D group, #17, F group, and #21, trisomy on chromosomes A group, #6, 7, 8, 9, 16, and X, nullisomy on chromosome #22, in the karyotype analysis. All of the nine cells containing DMS showed karyotypic abnormalities, while DMS were not seen in the cells with normal karyotypes. Marker chromosomes ranging from 12 to 16, other than DMS, were seen in all of the nine cells. The number of DMS varied considerably among the cells, ranging from 17 to 133. The number of DMS correlated neither with the total number of the chromosomes nor with the number of marker chromosomes. There was no chromosomal abnormality indicating homogeneously staining regions in all of the cells observed in this tumor tissue. In the course of in vitro culture, both the cells with DMS and DMS within the cells gradually diminished in number.