[Stereotaxic biopsy of intracranial processes: validity of histologic diagnosis]

The diagnostic validity of stereotactic intracranial biopsies was investigated in 70 patients retrospectively. In 56 cases (80%) the presence of a neoplastic lesion as well as its grade of malignancy was proved by cytological, histological and immunohistochemical techniques. An inflammatory or vascular lesion was found in 8 patients (11.4%). In 6 patients (8.6%) the nature of the lesion remained unclear because of nonspecific histological findings. In 27 cases a correlation was found between the biopsy specimens and corresponding material obtained during open surgery or autopsy. 24 concordant results were found (88.9%). In one case a malignant tumour was classified only according to the findings obtained at operation. In two cases subsequently diagnosed as glioblastoma biopsy reported a higher differentiated astrocytoma and a non-neoplastic lesion, respectively. These results confirm stereotactic biopsy of intracranial lesions as a method with low complication rate and high diagnostic validity.