Do maxillary sinus retention cysts reflect obstructive sinus phenomena?

Objective: To determine the relation of maxillary sinus retention cysts (RC s) to ostiomeatal complex (OMC) obstruction and anatomic variation of the p aranasal sinuses. Methods: The results of 410 computed tomographic scans of the sinuses order ed by otolaryngologists in an academic center during a 1-year period were r eviewed. Computed tomographic scans with maxillary sinus RCs were studied t o determine cyst characteristics, the Lund score, OMC size and patency, and the presence of anatomic variations. Statistical analysis was conducted to determine the relation of RCs to these factors. Results: The incidence of RCs was 12.4% (51 cases). The mean patient age wa s 41.3 years, with a female-male ratio of 2.4:1. Nine cases demonstrated bi lateral cysts, allowing 42 unilateral cases to be analyzed with the nondise ased side as a control. The mean cyst size was 1.56 cm, and cysts were most commonly located inferiorly (30 [50%]) and were solitary (45 [88%]). The R C side had a higher mean Lund score than the control side (2.62 vs 1.93; P= .008, Wilcoxon signed rank test). Of the cyst sides, 18 (43%) demonstrated OMC occlusion, vs 15 (36%) for the control side (P=.55, McNemar test). The mean OMC size was smaller for the cyst side vs the control side (0.77 vs 1. 35 mm; P=.13). No association was found between RCs and concha bullosa or H aller cells (P=.45 and P=.39, respectively). Conclusions: Maxillary sinus RCs do not reflect persistent obstructive path ology of the OMC, and are not associated with potentially obstructive anato mic sinus variations. Consideration should be given to not scoring RCs as p ositive disease during Lund staging.