Calcification in chronic maxillary sinusitis: comparison of CT findings with histopathologic results

Abstract

Background and purpose: It is important to differentiate fungal from nonfungal sinusitis in order to determine the optimal treatment for chronic sinusitis. The purpose of this study was to describe the CT findings of calcifications in chronic fungal and nonfungal maxillary sinusitis.

Methods: Five hundred ten patients with pathologically proved chronic maxillary sinusitis were studied with unenhanced CT before undergoing sinonasal surgery. In 36 patients, the CT scans were reviewed retrospectively to ascertain the shape and location of intrasinus calcifications.

Results: Calcifications were found in 20 (51%) of 39 patients with fungal sinusitis and in 16 (3%) of 471 patients with nonfungal sinusitis. Direct histopathologic correlation was performed in two of 16 patients with nonfungal sinusitis who had intrasinus calcification. The location of intrasinus calcification was central in 95% of the patients with fungal sinusitis and peripheral in 81% of those with nonfungal sinusitis. Although calcifications with a nodular or linear shape were seen in both fungal and nonfungal sinusitis, fine punctate type calcifications were seen only in those with fungal sinusitis (50%) and round or eggshell type calcifications only in those with nonfungal sinusitis (19%).

Conclusion: Intrasinus calcifications are different in location and shape between fungal and nonfungal maxillary sinusitis. Although intrasinus calcification is uncommon in nonfungal sinusitis, the CT finding of intrasinus calcification may be helpful for differentiating fungal from nonfungal maxillary sinusitis.

fig 1.

Calcification in aspergillosis. A, Coronal CT scan shows irregular nodular (short arrow) and fine punctate (long arrow) calcification within the inflammatory tissue at the center of the opacified left maxillary sinus. B, Photomicrograph of surgical specimen shows mottled calcifications (arrow) embedded within the fungal mycelium (hematoxylin-eosin, original magnification ×100). C, Darkly stained fungal hyphae (short arrows) are seen around the nodular calcification (long arrow) (Gomori's methenamine silver stain, original magnification ×100).

fig 2.

Calcification in aspergillosis. Coronal CT scan shows nodular (short arrow) and linear (long arrow) calcifications located centrally in the right maxillary sinus. fig 3. Calcification in nonfungal sinusitis. A, Smoothly marginated linear calcification (large arrow) is seen near the floor of the left maxillary sinus. The calcification is located at the periphery of the sinus and there is a thin layer of soft-tissue density (small arrows) separating the calcification from the sinus wall. B, Photomicrograph of surgical specimen shows calcification (short arrow) within the thickened fibrotic submucosal layer of the maxillary sinus. Vascular congestion with dilated capillaries (long arrows) is seen in the edematous superficial submucosal layer (hematoxylin-eosin, original magnification ×100).

fig 4.

Ossification in nonfungal sinusitis. A, CT scan shows round and eggshell lesions (arrow) in the left maxillary sinus. The calcific density lesions are located near the inferior wall of the sinus and are separated from the bony wall. B, Photomicrograph of surgical specimen shows well-marginated round woven bone (short arrow) embedded within the fibrotic submucosal layer of the maxillary sinus. There is glandular hyperplasia (long arrow) caused by inflammation in the submucosa of the maxillary sinus (hematoxylin-eosin, original magnification ×100).