Zeitschrift für Zytologie und Histologie

Background: Intraoperative frozen section (IOFS) diagnosis of brain tumours plays an important role in assessing the adequacy of the sample and determining the treatment plan.

Objective: To investigate the diagnostic accuracy between IOFS and permanent paraffin-embedded sections in the endpoint of surgery.

Method: The authors reviewed the histopathological results of 383 brain tumours, including IOFS and permanent histological diagnosis. The cases were classified into three diagnostic compatibilities (i) Perfect fit; the diagnosis of IOFS was identical to the permanent diagnosis, (ii) Partial compatibility; IOFS diagnosis was not incorrect but was too broad to be considered full compatibility, (iii) Conflict; IOFS diagnosis is completely different from the permanent diagnosis. The permanent diagnosis used as a primary criterion was compared to the IOFS diagnosis and recurrence rate using different statistical methods.

Results: The mean age of the whole cases was 37-years with male: female ratio 1:2. Around 84% of the patients underwent craniotomy and tumour resection, while 15% only underwent tumour biopsy. Approximately, 53.8% of the cases revealed perfect matching in the diagnosis between IOFSs and permanent sections, while 16.2% of the cases revealed complete mismatching in the diagnosis between the sections. The remaining 30% of the cases showed partial compatibility in the diagnosis between the two diagnostic methods. There was no significant difference in recurrence rate among all cases of different diagnostic compatibility (P-value= 0.54).

Conclusion: There is a diagnostic discrepancy between IOFSs and permanent sections. However, cases that revealed no consensus in the diagnoses showed no negative effect on the patient outcome. Further studies should be conducted to explore the reasons of this conflict in the diagnosis between the two diagnostic methods.