Brain stem expansive lesions: stereotactic biopsy for a better therapeutic approach.

CT diagnosed brain stem malignant lesions were in the past almost always treated with radiation therapy (RT). Eventually this turned out to be a grave mistake. With stereotactic serial biopsies of all brain stem expanding lesions we have been able to verify the histological nature in all cases but two and to prevent a blind therapeutic approach. In 24 patients bearing CT diagnosed expansive lesions into the brain stem 68 samples were taken during 24 stereotactic procedures. In 8 patients surgical removal of the expanding lesion was attempted after stereotactic biopsy.