Allelic loss on chromosome 22 correlates with histopathological predictors of recurrence of meningiomas.

Meningiomas are common tumors of the nervous system. Although usually benign, they may exhibit variable degrees of aggressiveness. Their probability of recurrence after subtotal resection has been correlated with several histological parameters. Independently, a loss of chromosome 22, as evidenced either by cytogenetics or by somatic loss of alleles, has been observed in about half of the cases studied. In 34 meningiomas we have examined the relationship between loss of chromosome 22 alleles and 6 histological predictors of recurrence. Significant correlations were found for 3 of these, i.e. prominent nucleoli (p less than 0.002), microscope count of mitoses (p less than 0.05) and nuclear pleomorphism (p less than 0.02). Correlation with the other 3, i.e. sheeting of cells, vascularity and micronecrosis, did not reach significance. Total tumor score, defined by the sum of the individual scores for these 6 parameters, was strongly correlated to allelic loss (p less than 0.0001). Thus, the loss of chromosome 22 alleles, which possibly contribute to the inactivation of tumor-suppressor gene(s), might be a potent genetic marker of the aggressiveness of meningiomas.