Poorly differentiated sinonasal adenocarcinoma

There is an enhancing destructive mass centered about the right maxillary sinus and ethmoid air cells with extension into the orbit and nasal cavity measuring approximately 4.9 cm x 4.0 x 3.6 cm (CC x AP x TV).

The superior component of the mass invades the cribriform plates and fovea ethmoidalis with extension into the olfactory fossa and floor of the anterior cranial fossa The anterior component invades the nasolacrimal duct and anterior ethmoid artery notch. There is also soft tissue mass extension into the right premaxillary soft tissues by approximately 3 mm. There is a destruction of ethmoid sinus septations and destruction of the lamina papyracea and orbital floor. The orbital component involves the mass lateral rectus, inferior rectus, and inferior oblique muscle with extension into the intraconal fat planes contacting the medial margin of the optic nerve sheath complex. There is associated proptosis. The posterior aspect of the lesion involves the pterygopalatine fossa and sphenopalatine foramen.

Centered within the right maxillary sinus there is a 4.1 x 3.5 x 5.0 cm mass (AP by TR by CC). The mass is heterogeneous hypointense on T2-weighted imaging with corresponding hypointensity on T1-weighted imaging and heterogeneous enhancement. The mass extends superiorly to the level of the cribriform plate with associated cortical destruction and enhancement of the right olfactory nerve, suggestive of perineural spread. The mass extends medially to the nasal septum, inferiorly to the superior aspect of the hard palate, and posteriorly into the nasopharynx. There is thickening of the right maxillary sinus walls which could relate to chronic osteitis. There are mucous secretions in the frontal sinuses and right sphenoid air cells, likely related to obstruction of the frontal ethmoidal recess and sphenoethmoidal foramen. The mass extends through the ipsilateral orbital floor and lamina papyracea with associated cortical destruction and proptosis. There is effacement of the extraconal fat as well as the intraconal fat separating the inferior and medial rectus. There is obliteration of the fat plane between the inferior rectus muscle and the mass as well as the inferior border of the medial rectus muscle for which invasion is not excluded. The mass extends through the anterior maxillary wall into the premaxillary fat. There is invasion of the infraorbital nerve foramen. There is asymmetric enhancement just inferior to the orbital apex as well as the medial right middle cranial fossa which may represent tumor spread versus venous engorgement.

There is loss of normal signal on T1-weighted imaging within the right vidian canal, pterygopalatine fossa, and retroantral fat, consistent with tumor invasion. There is questionable perineural spread into the right foreman rotundum. There is asymmetric enhancement about the right anterior clinoid process and optic canal. In addition, there is asymmetric enhancement of the right pterygoid venous plexus, which likely reflects a combination of intravenous engorgement and susceptibility artifact related to patient's dental hardware.

Other findings include a focus of wispy enhancement with corresponding susceptibility artifact within the central pons, suggestive of a capillary telangiectasia. There is an additional focus of susceptibility artifact along the lateral right medullary pontine junction, suggestive of remote microhemorrhage versus an additional capillary telangiectasia.