Reliability of stereotactic biopsy. A model to test the value of diagnoses obtained from small fragments of nervous system tumors.

Because of the variability of the structural features of cerebral tumors, the characteristics observed in biopsy samples may not be representative of the whole neoplasm. The reliability of cerebral stereotactic biopsy is therefore greatly debated. In order to test the value of diagnoses based on biopsy samples, the authors compared histological and cytological data obtained from a small fragment of a tumor with the definitive diagnosis obtained from surgical or necropsy specimens. An analysis of 64 cases is reported, where a correct diagnosis from the biopsy sample was achieved in 92.2% of the cases. Neuroglial tumors were more difficult to characterize than other types of intracranial tumors, with an accuracy of 81.5%.