INFLAMMATORY PSEUDOTUMOR OF THE MAXILLARY SINUS - CT AND MR FINDINGS IN 6 CASES

OBJECTIVE. Inflammatory pseudotumor is a chronic inflammatory lesion o f unknown origin. The purpose of this study was to analyze the CT and MR findings in six cases of inflammatory pseudotumor of the maxillary sinus in order to determine if there were any imaging findings that di stinguish this lesion from the more common type of pseudotumor that oc curs in the orbit. MATERIALS AND METHODS. Six patients with pseudotumo r of the maxillary sinus were identified retrospectively. The diagnosi s was based on biopsy specimens. Their CT scans and MR images were stu died by two radiologists to identify specifically the presence of soft -tissue disease and the presence and type of any bone involvement. RES ULTS. CT and MR images showed some degree of involvement of the bony w all in all cases. All patients had a soft-tissue mass with mild enhanc ement on CT scans and intermediate signal intensity on both T1- and T2 -weighted MR images. CONCLUSION. Our experience shows that inflammator y pseudotumor of the maxillary sinus causes bone changes on CT and MR images, findings that mimic a malignant tumor. Bone involvement appear s to be more common in pseudotumor of the maxillary antrum than in its orbital counterpart.