CT differential diagnosis of fnngal ball in paranasal sinus caused by different mycotic pathogenic agents

Abstract

Objective To evaluate CT characteristics of fungal ball in paranasal sinus caused by different fungi and to enhance differential diagnosis.Methods CT results and clinical data of 74 patients with fungal ball arising from the paranasal sinuses proved by histopathology from 2007 to 2009 were analyzed retrospectively.The CT characteristics of fungal ball in paranasal sinus caused by different fungi were compared using x2 test with P ＜ 0.05 considered statistically significant.Results Among 74 mycotic pathogenic agents,aspergillus was found in 58 cases (including 36 cases with aspergilhs flavus,15 cases with aspergillus fumigatus and 7 with aspergillus versicolor),the others including 5 cases with penicillium,6 cases with schizophyllum commune,and 5 cases with scedosporium apiospermum.There were significant differences in the number of sinus involved ( single sinus involvement was seen in 29 cases caused by aspergillus group and 2 cases caused by non-aspergillus-group,respectively,with x2 =7.245,P =0.007 ),the incidence of fungus ball in ethmoid sinus [ 39.7％ ( 23/58 ) of cases caused by aspergillus group and 81.3 ％ ( 13/16 ) of cases caused by non-aspergillus-group,respectively,with x2 =8.685,P =0.003 ] and calcification (40 of 58 cases caused by aspergillus group and 5 of 16 cases caused by non-aspergillus-group,respectively,with x2 =7.485,P =0.006 ),the location of calcification ( 26 of 40 cases with central calcification and 14 of 40 cases with peripheral calcification in cases caused by aspergillus group,while all of 5 cases caused by non-aspergillus-group with peripheral calcification,x2 =7.697,P =0.006).However,there was no significant difference in the incidence of bilateral lesions ( x2 =1.002,P =0.317 ),maxillary sinus involvement ( x2 =0.020,P =0.888 ),sphenoidal sinus involvement ( x2 =0.704,P =0.401 ),frontal sinus involvement ( x2 =0.126,P =0.723 ),bony sclerosis ( x2 =2.024,P =0.155 ),lamellar calcification (x2 =2.045,P =0.153 ),complication of nasal polyps( x2 =0.018,P =0.893) and submucosal cyst( x2 =0.779,P =0.378 ).Conclusions The common CT characteristics of fungal ball in paranasal sinus are unilateral sinus involvement with inhomogeneous high-density soft tissue and lamellar calcification.The CT findings of fungal ball caused by non-aspergillus-group are ethmoid sinus involvement and calcification located on the periphery instead of the center of fungal ball. Key words: Paranasal sinus; Fungi; Tomography, X-ray computed