Sinonasal carcinoma associated with inverted papilloma: A report of 16 cases

Objectives: To analyse the characteristics and outcome of patients with carcinoma associated with inverted papilloma, and find predictors of associated malignancy. Methods: The medical records of 228 patients who were diagnosed with IP between January 1990 and December 2010 were retrospectively reviewed. Out of 228 patients, 16 were also diagnosed with carcinoma. We evaluated their clinical characteristics, treatment modalities, and survival outcomes. Results: The incidence of carcinoma associated with IP was 7.0%. Fourteen were synchronous carcinomas and two were metachronous. Tumours arising inside the frontal sinus or the frontoethmoidal recess were more likely to be associated with carcinoma. Patients who had a stage of T2 or less had a much better outcome than those who had a stage of T3 or greater (disease-free period, 84.8 months vs. 5.7 months, p < 0.001). Conclusion: Tumours originating in the frontal sinus or frontoethmoidal recess have a tendency to be associated with carcinoma. As most (87.5%) of the carcinomas were diagnosed at the same time as the inverted papilloma, complete histological examination of the whole excised tumour is warranted because early diagnosis and treatment is essential as T2 and lower stage carcinomas had a strikingly better prognosis than T3 and higher stage carcinomas.