Presentation
Right proptosis.
Patient Data
Expansion and sclerosis of the right frontal bone, involving the right orbital roof which also shows a cystic component measuring 2x3 cm.
The frontal sinuses are nearly obliterated.
An expansile right frontal bone intradiploic osteolytic lesion, showing thin lobulated bony wall, and focal posterior wall interruptions. It is measuring 2.3 x 3.2 x 2.8 cm in AP, SS and CC dimensions. It shows internal fluid signal of T1 high signal, T2 marginal high and central low intensity signal, and no diffusion restriction. It is anteromedially connected to the small-sized right frontal sinus. Unremarkable adjacent brain parenchyma.
2nd presentation after 5mths
Denovo right orbital lateral wall subperiosteal extension noted measuring 2.6 x 1 cm in AP, SS dimensions.
Case Discussion
Features are suggestive of bilateral frontal sinuses fibrous dysplasia and associated right frontal mucocele formation with lateral orbital subperiosteal extension. Frontal sinus mucocele is a rare association with fibrous dysplasia of frontal sinuses.