Uncommon anatomic variations in patients with chronic paranasal sinusitis

OBJECTIVE: Some uncommon anatomic variations would be encountered with the increasing number of patients with chronic paranasal sinusitis who have undergone functional endoscopic sinus surgery. The correct identification and proper treatment for these variations are important. STUDY DESIGN AND SETTING: A retrospective study of serial computed tomography scan images was conducted in 100 patients collected randomly. Uncommon anatomic variations were recorded and clinical features were analyzed. RESULTS: Five (5%) cases with uncommon anatomic variations were found. These variations included bilateral pneumatization of uncinate process (1%), large uncinate process mimics the middle turbinate (1%), nontraumatic protrusion of orbital contents through dehiscence of lamina papyracea (1%), and nasal septal pneumatization (2%). Two of these 5 cases caused some modifications of routine functional endoscopic sinus surgery procedures and another 2 variants commanded further caution during routine uncinectomy. CONCLUSION AND SIGNIFICANCE: Uncommon anatomic variations, though unusual, are not rare in chronic paranasal sinusitis patients. Procedures should be tailored for most of these special conditions.