Diagnosis and treatment modalities of sinunasal inverted papillomas.

Background: Today, etiology and pathogenesis of sinunasal inverted papillom as (IP) remain unknown. Surgical approaches and extension of surgical resec tions are still controversial, Patients and Methods: In a retrospective stu dy we reviewed the charts of 90 patients with sinunasal IF. Using external (n = 78) or endonasal (n = 12) approaches the tumors were completely resect ed in all cases. 57 cases were investigated for human papilloma virus (HPV) by immunohistochemistry. Results: 60 % of IP extended beyond one single pa ranasal sinus or the nasal cavity. 7% infiltrated adjacent anatomical struc tures (subcutis, orbit, anterior skull base). The recurrence rate was 19% a fter a mean interval of 8,2 month. Associated malignancy was found in 7 cas es (7.7%). HPV was detected in 9% of IF. Postoperative complaints were noti ced by 27 % of endonasal and 35 % of transfacial operated patients. Conclus ions: Because of the advanced tumor stage in the majority of cases, usually a radical transfacial surgical excision of IP is required. Endonasal appro aches are feasible in selected cases, but surgery has to be more extensive compared to surgery for sinunasal polyposis. In the literature and in our e xperience IP is rarely associated with carcinoma (10% in literature) and th e incidence of malignancy is not increased in recurrent IF. Using PCR, the prevalence of HPV ranges from 7 to 69% in the literature. Our immunohistoch emical results support a rather low prevalence of HPV in IP.