CYTOGENETICAL FINDINGS OF RECURRENT MENINGIOMAS - A STUDY OF 10 TUMORS

Cytogenetic analyses of 10 cases of recurrent meningiomas growing in c ulture between 1-10 days are reported, of which seven showed benign mo rphology, one atypical, and two, malignant features. Normal karyotypes with nonclonal alterations were found in three cases, one case with o nly monosomy 22, and complex karyotypes in the remaining six. Four cas es were hypodiploid, one pseudodiploid, and one hyperdiploid. The chro mosomes most often involved in structural rearrangements were 1, 7, an d 14 and the losses were chromosomes 7, 10, 14, 15, 18, and 22. Ring c hromosome, dicentrics, double minutes, and association between satelli tes were found in one case. These complex karyotypes with hypodiploidy , structural rearrangements, and other markers in recurrent meningioma s may indicate aggressive tumor characteristics.