Retrospective Study on Accuracy of Intraoperative Frozen Section Biopsy in Spinal Tumors

OBJECTIVE: Histologic types and grades are critical in the diagnosis and treatment of spinal tumors. Intraoperative frozen section is a fast and easy method in confirming pathologic diagnosis during the operation. This study was undertaken to reveal the accuracy of intra-operative frozen section biopsy in order to make proper treatment plans. METHODS: This retrospective study concerned patients who underwent spinal tumor surgeries from 1 January, 2012 to 31 December, 2016. Frozen section biopsy and permanent biopsy were compared, and cases that had differences were counted. RESULTS: Thirty-seven cases out of 324 patients had discrepancies (11.4%). In discrepant cases 11 cases were ependymoma (29.7%) and 6 cases were schwannoma (16.2%). Among 34 patients who were finally diagnosed with an ependymoma, 11 cases had discrepancies, which was the highest mismatch rate among tumor final pathologic types. By frozen biopsy, astrocytoma (n=5) and ependymoma (n=5) turned out to be the most discrepant pathologic types and 16 frozen section biopsy cases were "null." Frozen biopsy astrocytoma (n=5) mostly turned out to be ependymoma in 4 cases. CONCLUSIONS: Pathologic findings from frozen biopsy for spinal cord tumors could not be corresponded to final diagnosis, especially when the results of frozen biopsy were ependymoma or astrocytoma. Therefore careful decision making for treatment plans is required.