Chromosome abnormalities in meningiomas.

Cytogenetic analyses of eight meningiomas grown in culture for 1 week are reported. Normal karyotypes were found in three cases and hypodiploidy in the remaining five. In the five hypodiploid meningiomas, one chromosome #22 was missing in four cases, and one case exhibited a 22q- deletion. In four of these five cases, chromosome #14 was either lost or altered. Chromosome #1 was lost or altered in three, and chromosome #6 in two. These findings lend further support for the association of total or partial loss of chromosome #22 in meningiomas and suggest the involvement of other chromosomes in the clonal evolution of these tumors.