Diagnostic yield in computed tomography guided stereotactic biopsies.

Fifty three patients underwent computerised tomography (CT) guided stereotactic biopsies from different CT defined zones of attenuation with the Leksell stereotactic apparatus from October 1993 through January 1995. Multiple lesions were seen in 16 cases and 3 of them had multiple rim enhancing lesions. Astrocytoma was the most common histological diagnosis and thalamus was the commonest site of these tumours. The overall positivity rate was 98.2%. Positive yield from the centre of the lesion, peripheral and perilesional areas was 92.1%, 54.7% and 17.6%, respectively. The definite pathological diagnosis was made in 81.1% of cases. Post-operative neurological worsening was seen in 6 patients, of which 2 recovered without any surgical treatment, in 1 patient ventriculo-peritoneal shunt was done post-biopsy whereas in another evacuation of hamatoma was done which relieved headache and vomiting while 2 patients (3.7%) died.