Accuracy of intraoperative frozen section in detection of acute invasive fungal rhinosinusitis

Context.-Acute invasive fungal rhinosinusitis (AIFRS) is an aggressive form of fungal sinusitis, which remains a significant cause of morbidity and mortality. Early diagnosis and intervention are keys to improving patient outcomes. Intraoperative consultation has shown promise in facilitating early surgical intervention, but the accuracy of frozen section has not been clarified in this setting. Objectives.-To assess the accuracy of frozen-section diagnosis in patients with clinically suspected AIFRS. Design.-All cases of clinically suspected AIFRS during a 10-year period (2009-2019) were retrospectively reviewed. The frozen-section results were compared with the final permanent sections as well as the tissue fungal culture results, following which the accuracy of frozen section was determined. Results.-Forty-eight patients with 133 frozen-section evaluations for AIFRS were included in the study. Thirty of 48 patients and 61 of 133 specimens were positive for AIFRS on final pathology. Of 30 positive patients, 27 (90%) had at least 1 specimen diagnosed as positive during intraoperative consultation; among the 61 positive specimens, 54 (88.5%) were diagnosed as positive during intraoperative consultation. Of 72 negative specimens, all were interpreted as negative on frozen section. Thus, frozen sections had a sensitivity of 88.5% (95% CI, 0.78-0.97), specificity of 100% (95% CI, 0.94-1), positive predictive value of 100% (95% CI, 0.92-1), and negative predictive value of 90.6% (95% CI, 0.82-0.97). Conclusions.-This study represents the largest series assessing the diagnostic accuracy of frozen section analysis in AIFRS. These findings are useful in frozen section-informed intraoperative decision making.