Unilateral Paranasal Sinusitis Detected by Routine Sinus Computed Tomography: Analysis of Pathology and Image Findings

The aim of this study was to evaluate the histopathological findings of unilateral paranasal sinus disease dominated by maxillary sinus opacification on routine non-contrast enhanced paranasal sinus CT. We performed a retrospective analysis of routine paranasal sinus CT conducted between March 2003 and April 2007. Unilateral maxillary sinus opacification (with or without ipsilateral ethmoid or frontal sinus involvement) was identified. All scans were reviewed by two radiologists tinder standard soft-tissue and bone windows. The features of maxillary sinus bony erosion, wall thickening, calcification, tissue invasion, and histopathology were noted. Tn total, 1256 consecutive scans were reviewed, 134 (10.7%) with unilateral sinus involvement. Histopathology was available for 76 (56.7%) patients including 55 (72.4%) inflammatory disease (acute and chronic), 18 (23.7%) fungal disease, and three (3.9%) neoplasia cases. A single case of malignant lymphoma and two cases of inverted papilloma were also present. Fungal sinusitis was associated with significantly more intrasinus calcification (n = 13; 72.2%) and maxillary sinus-wall thickening (n = 16; 88.9%) than was chronic rhinosinusitis (n - 6; 10.9% and n = 20; 36.4% respectively; both p < 0.05). In summary, the incidence of unilateral paranasal sinus disease dominated by maxillary sinus opacification on routine paranasal sinus CT scans was 10.7% and the condition is considered uncommon. Chronic rhinosinusitis (fungal and non-fungal origin) comprised up to 96% of cases, with a 4% to 7% incidence of neoplasia.