 There is an expansile T1 hypointense, T2 hyperintense lesion in the left frontal sinus measuring approximately 1.6 x 1.9 x 2.5 cm in the AP, transverse, and craniocaudal dimensions extending into the left frontoethmoidal recess with no appreciable internal contrast enhancement. The lesion extends to the left superior medial aspect of the orbit with no mass effect on the globes. Lesion abuts the left superior oblique muscle. There is associated osseous remodeling including dehiscence involving the left superior medial orbital wall better seen on recent CT. There is T2 hyperintense signal with enhancement in the lateral left frontal sinus and to a lesser degree in the anterior ethmoids thought to be due to obstructed secretions/inflammation. There is also complete opacification of the left maxillary sinus with peripheral enhancement, which is likely inflammatory.The brain demonstrate patchy periventricular and subcortical white matter FLAIR signal abnormality which is nonspecific but likely due to moderate chronic small vessel ischemic disease. The ventricles and sulci are mildly prominent likely due to age-related volume loss. There are small nonspecific foci of microhemorrhage in the left superior temporal lobe. The cisterns remain patent. There is no midline shift or mass effect. There is no diffusion abnormality. No extra-axial fluid collection is identified.Normal flow-voids are demonstrated in the major intracranial vascular structures. The sagittal images show retroodontoid pannus which is incompletely imaged.
1. Expansile lesion in the left frontal sinus with bony dehiscence involving the left superior medial orbit most likely represents a mucocele. Given the absence of internal enhancement, neoplasm would be much less likely. There is mass effect on the left superior oblique muscle. No significant mass effect on the globe.2. T2 hyperintense, enhancing mucosal thickening in the left frontal sinus more laterally and anterior ethmoids likely due to obstructed secretions/inflammation. There is also diffuse opacification of the left maxillary sinus also likely due to inflammation.