Discordance in preoperative and postoperative histopathology of sinonasal tumors

Background: Head and neck surgical pathology has been shown to be prone to histopathologic diagnostic error that can adversely impact patient care due to inappropriate management. Sinonasal tumors, in particular, present a diagnostic challenge given the relative rarity and diversity in histology and thus may have higher rates of discordant histology. Objective: The purpose of this study is to determine the rate of discrepancy between preoperative and postoperative diagnoses of sinonasal tumors. Methods: Retrospective chart review was performed on 52 patients treated for sinonasal tumors between January 2013 and December 2016. Initial diagnosis on preoperative biopsy was compared to postoperative diagnosis rendered at a single tertiary care referral center. A discrepant diagnosis was regarded as any change in diagnosis that resulted in further refinement of therapy or prognosis. Results: Eleven (21.2%) patients had discrepancy between the preliminary pathology and postsurgical diagnosis. Of these diagnoses, four involved a change from a benign to a more aggressive benign or malignant process, three involved reclassification of a malignant tumor to a more aggressive histology, and four involved change from an aggressive process to benign histology. In all 11 cases, alteration in management strategy was rendered. The majority of discordant diagnoses were of fibro-osseous lesions and small round blue cell tumors. Conclusion: Sinonasal tumors exhibit a high degree of discordance from preoperative to postoperative diagnosis. Critical decision-making should be reserved until careful review of operative specimens is performed to minimize patient morbidity and unnecessary interventions.