Presentation
Chronic headaches with right proptosis.
Patient Data
Total opacification of the frontal sinuses. Expansile right frontal sinus with smooth scalloping of its bony walls, containing area of high signal on T1 and low signal on T2 (protein-rich content) with mild peripheral enhancement. A mass effect is noted on the orbital muscles, optic nerve, lacrimal gland and the ocular globe with proptosis grade 3.
Case Discussion
MRI features most consistent with right frontal mucocele.
The frontal sinus is the most common site of paranasal sinus mucocele. Mucoceles most likely occur as a result of obstruction of the ostium of a sinus due to inflammation, trauma, mass lesion, etc., with resultant accumulation of mucus and eventual expansion of the sinus.