RESUMO
While stereotactic biopsy increases the accuracy of obtaining appropriate tissue for precise diagnosis, inconclusive diagnostic lesions can still be observed frequently. We present a review of 43 patients with inconclusive diagnostic samples in stereotactic biopsy between June 1989 and June 1994. inconclusive diagnostic lesions were found in 43 patients(17.9%); the biopsy of these patients showed reactive gliosis in 22, foam cell infiltration and/or demyelination with coagulation necrosis in 8, chronic inflammatory cell infiltration with necrosis, fibrosis in 6, no evidence of tumor in 5, and ganglioglial lesion in 2. The final diagnosis was based on histological findings of permanent paraffin sections after rebiopsy or open surgery, close follow-up CT/MRI scan findings, clinical features and/or history, and serological studies;neoplasm 16, infarction/leukodystrophy 8, infection/inflammation 4, granuloma 1, and no confirmative diagnosis 4, In conclusion, rebiopsy or open surgery is recommended if the lesion is suspected to be a neoplasm, and the patient is closely observed with repeated radiological studies if the lesion is suspected to be benign. This study provides evidence that in some cases an accurate histopathological diagnosis can not be made with stereotactic biopsy and therefore, further investigations are needed in such inconclusive cases.