Role of stereotactic biopsy in multifocal brain lesions: considerations on 100 consecutive cases.

One hundred patients affected by multifocal brain lesions were investigated by serial stereotactic biopsy. Systemic diseases and primary neoplasms elsewhere were previously ruled out. The histological diagnosis obtained in this series comprises malignant gliomas in 37% of patients; primary non-Hodgkin's brain lymphoma in 15%; metastatic brain tumours in 15% (no evidence of the primary tumour at the time of stereotactic surgery); low grade gliomas in 12%; infective diseases in 10% (including brain abscesses and multifocal viral encephalitis); and ischaemic lesions in 6%. In addition, two patients with germinomas, two with primitive neuroepithelial tumours, two with multiple telangiectases, and one with a teratoma were also included in this series. Histological findings obtained by stereotactic procedures guided the choice of treatment, avoiding the risks of blind treatments. Indications and future perspectives for stereotactic surgery in multifocal brain lesions are discussed with emphasis on advances in diagnostic and therapeutic tools.