Diagnostic Accuracy of Office Biopsy for Inverted Papilloma

BackgroundWith a 10% risk for malignant transformation to squamous cell carcinoma (SCC), the treatment of inverted papilloma (IP) is surgical resection. Biopsy of IP can be helpful for diagnosis, but there are accuracy limitations.ObjectiveTo determine the diagnostic accuracy of office biopsy in patients who underwent surgical resection for sinonasal papilloma, and to examine clinical and pathological factors that impacted this accuracy.MethodsThis was a retrospective review of patients who underwent resection of sinonasal papilloma at a tertiary care center from January 2015 to April 2025 and had office biopsies performed at the same institution before surgery. Patient demographic and tumor characteristics were reviewed. We compared the accuracy of office biopsy against the final pathology from surgical resection.ResultsA total of 94 patients were included. Mean age was 59.6 (±12.5) years, with 69.1% male. Final pathology revealed 72 (76.6%) sinonasal papilloma without dysplasia, 19 (20.2%) sinonasal papilloma with dysplasia, and 3 (3.2%) SCC in situ. 13.9% (10/72) of the papilloma without dysplasia cases had false negative biopsies showing inflammatory lesions, while none of the pre-malignant papillomas had a false negative (non-neoplastic) biopsy (<i>P</i> < .001). The false negative biopsy cases were significantly associated with contralateral pathology on CT (50.0% vs 12.9%, <i>P</i> = .005) and concurrent inflammatory polyp (40.0% vs 4.8%, <i>P</i> < .001). Tumor characteristics were not significantly associated with higher rates of false negative biopsy.ConclusionsInaccurate biopsy results were mainly attributed to concurrent inflammatory processes. With a false negative rate of 14% on office biopsy, proceeding to surgical resection is warranted when there is a strong clinical suspicion for IP.