Growth potential of acoustic neuromas.

Tumor samples from 32 patients with acoustic neuroma operated with translabyrinthine approach were analyzed with flow cytometric technique with respect to ploidy and cell cycle phase distribution. In all cases the diagnosis of acoustic neuroma was verified histologically, two patients had Recklinghausen's disease. None of the tumors showed aneuploid cell lines. Median S-phase fraction was 6.8% (range 1.4 to 19.9%). The spread of S-phase values had a greater range for the smaller tumors (volume less than or equal to 2 cm3) of the material. There was no correlation neither between the fraction of cells in S-phase and age of the patient, nor between the fraction of cells in S-phase and tumor size. The present finding with a great variability in S-phase values does not support an expectant attitude regarding surgical intervention in patients with acoustic neuromas.