Brain stem expanding lesions: stereotactic diagnosis and therapeutical approach.

In most cases of brain stem expansive lesion a surgical approach is possible, but in each patient it must be evaluated if the surgical risk is proportional to the therapeutic result. Sometime surgery is limited to a biopsy sample, particularly in malignant lesions. We started stereotactic serial biopsy sampling in all CT or NMR intraaxial brain stem expansive lesions as a preliminary diagnostic procedure. The aim is to look for benign well delimited lesions that we consider for surgical removal or to drain haematomas and abscesses. 35 patients with brain stem expansive lesions were submitted to 47 surgical procedures: 35 stereotactic biopsies (one each patient) and, among them, 12 were major surgical procedures (with craniotomy) for microsurgical removal of the expansive lesions. 15 patients were in paediatric age. Suboccipital transcerebellar approach was performed in 25 mesencephalic, pontine, bulbar expansive lesions and frontal approach was limited to 10 thalamo-mesencephalic lesions. There was no mortality. Two patients were stereotactically drained and definitively cured.