Chromosome 22 monosomy in a radiation-induced meningioma.

We report for the first time on the cytogenetics of a radiation-induced meningioma, in a patient without neurofibromatosis. Chromosome 22 monosomy was found in more than 50% of the cells examined. These findings seem to suggest that the same kind of chromosomal aberrations are found in both "idiopathic" and radiation-induced meningiomas and that a common etiopathogenetic mechanism might be at work in meningiomas of whatever origin.