Objective: To assess with computerized tomography (CT) the association of unilateral inverted papilloma (IP) and contralateral sinus inflammation.
Design: Retrospective analysis of CTfindings in a sample of patients with unilateral IP, a sample with other unilateral sinonasal tumors, and normal controls.
Patients and methods: Sixteen patients with unilateral IP comprised the study population. Nine patients with other unilateral sinonasal tumors (five with squamous papilloma, two with squamous cell carcinoma, and one each with adenocarcinoma and large cell carcinoma) were used as a comparison population. Patients undergoing maxillofacial CTfor nontraumatic orbital conditions comprised the control sample (n = 12 sides). Each patient's preoperative CT scan was evaluated with a modified Lund-Mackay scoring system. The scores for the sides opposite the IPs were compared with the sides contralateral to other sinonasal tumors as well as to normal controls.
Results: Analysis of all three samples' contralateral sides simultaneously using analysis of variance revealed a difference (p = 0.010). The contralateral sinus scores in IPs tended to be higher than the sides opposite the other sinonasal tumors (mean, 2.66 +/- 1.07 versus 1.18 +/- 0.76; p = 0.06). These in turn were higher than the normal controls (mean, 0.75 +/- 0.48; p < 0.02).
Conclusions: Unilateral IPs are associated with contralateral inflammation as detected by CT. This degree of contralateral inflammation is greater than that seen in other sinonasal tumors. The etiology of this association is unclear. A recent histological review suggested IP is an inflammatory polyp and not a true papilloma. Our data further suggest inflammation may be involved in the pathogenesis of IP. Further work is needed to better understand the pathophysiology and behavior of IP and to define its relationship to sinus inflammation.