Presentation
Long history of nasal stuffiness. Prior attendance. Worsening symptoms.
Patient Data
Expansion of the frontal sinuses, mainly on the left side with erosion of the anterior, posterior walls and the superior margin of the left orbit. The inner table of the skull has a large defect.
The mucocole extends into anterior cranial fossa, mildly indenting the left frontal lobe. Large defect in the planum sphenoidale.Inferiorly, it extends into the upper aspect of the left orbit compressing the globe.
Expansion of the left anterior ethmoid air cells with smooth erosion of the lateral wall of the ethmoids and extension into the medial extraconal space combined displacing the globe inferolaterally and causing proptosis.
Prior surgery of the maxillary sinuses with residual mucoperiosteal thickening bilaterally. Mucoperiosteal thickening of the bilateral sphenoid sinuses, more marked on the right side. The ethmoid air cells on the right side are also completely opaque.
Status post bilateral maxillary sinus surgery.
Mucosal thickening of both maxillary, sphenoid and ethmoidal sinuses.
Mucosal thickening of the frontal sinuses with fluid in an expanded left frontal sinus. The inner table of the left frontal sinus has a large bony defect. Compression on the underlying left frontal lobe but no extension or infiltration into the brain parenchyma.
Minor left proptosis.
Case Discussion
Paranasal sinuses mucoceles as demonstrated in this case are radiologically aggressive but histologically benign. Bony destruction arises due to obstruction from the mucocele and it can be profound.
The frontal sinus, as in this case, is particularly prone to developing mucoceles with 2/3 occurring in this sinus. Extension may be into the orbit, intra-cranial contents or both.
As with a good deal of head and neck imaging, CT and MRI complement each other in disease assessment. The CT illustrates the bony details elegantly with soft tissue outlined with MRI - together they complete the complete picture.
This was a histologically proven mucocele of the frontal sinus.