Cytogenetic studies in 50 meningiomas.

In a series of 50 meningiomas, cytogenetic studies showed that almost half had a normal diploid karyotype. The remainder had monosomy 22, some with a normal diploid line also present. The initial monosomy was often followed by further chromosome loss, and occasionally by structural abnormalities, some with distinctive characteristics. Chromosomes most often involved in structural rearrangements were 1, 14, 10, and 19, and those most often lost were 17 and Y. The type of chromosome abnormalities seen were similar to those described for senescent human cell cultures, which suggests that common chromosomal mechanisms may be operative in benign tumors and senescent cells. Although meningiomas occur more commonly in females, the chromosomally abnormal tumors are distributed evenly between males and females. Within the group of tumors with structural chromosomal abnormality, there seems to be a bias toward meningotheliomatous histology, but otherwise the karyotype changes seen independent of the histologic type of tumor.