An analysis of stereotactic biopsy of brain tumors and nonneoplastic lesions: a prospective clinicopathologic study.

BACKGROUND: Appropriate management of progressive, unverified brain lesions should be guided by conclusive pathological diagnosis. Stereotactic biopsy (SB) is established as a less invasive surgical procedure that provides diagnosis. In this prospective study, we analyzed the diagnostic difficulties and risk of SB in the various brain mass lesions, the rate of conclusive pathological diagnosis, and the rate of and the reasons for discrepancy between the intraoperative smear results and conclusive paraffin diagnosis.
METHODS: Using computed tomography (CT) and/or magnetic resonance imaging (MRI), 130 cases underwent SB procedure to assess intra-axial brain mass lesions. A CT-MRI fusion and a multiplanar image processing stereotactic program were used in cases who had lesions adjacent to the neurovascular and critical areas. The intraoperative evaluations were made with the smear preparations (SPs) of 1 or 2 biopsy specimens. The conclusive diagnosis was achieved by paraffin preparations of the remainder of the biopsies. The discrepancy between the smear results and the conclusive diagnosis was analyzed.
RESULTS: Conclusive histopathologic diagnosis was achieved in 99.23% of the cases. A discrepancy between smear results and conclusive diagnosis was detected in 6.98% of the conclusively diagnosed cases. The major reasons for the discrepancy were necrosis and improper quality of the preparations. There was no mortality, and hemorrhage-related morbidity was observed in 1 case (0.7%).
CONCLUSIONS: Necrosis and the improper quality of the smear preparations (SPs) can cause difficulties in establishing a histopathologic diagnosis in SB. Small tissue samples do not decrease the diagnostic yield with the new stereotactic technologies used by an experienced team consisting of a neurosurgeon, pathologist, and radiologist.