An ill-defined large soft tissue mass lesion filling the right ethmoidal, sphenoidal, and maxillary sinuses with intraorbital and intracranial extension causing right-sided proptosis. The mass is initially hyperdense, showing heterogeneous enhancement in the post-contrast study. There is destruction of the medial orbital wall and cribriform plate as well as the maxillary wall with a well defined cystic lesion seen exophytic from the right orbit suggestive of abscess formation.
Mucoperiosteal thickening is seen in the left maxillary, frontal, and ethmoidal sinuses.