Neuro-oncological problems in the histological diagnosis of stereotactic biopsies.

Stereotactic biopsy, together with CT and MRI, plays a very important role in the diagnosis of intracranial neoplasms and in their subsequent treatment. Serial neuroimaging-driven biopsies are considered the method of choice when dealing with gliomas, due to their well know morphological dishomogeneity; peritumoral tissues can also be investigated. Oncotype diagnosis, identification of malignancy grading and delimitation of the tumor are evaluated both with the quick perioperatory method of smears and then, in order to minimize errors, definitively evaluated on the paraffin-embedded specimens. Despite these precautions, several specific criteria must be taken into account in order to achieve the correct diagnosis.