Sinusitis can cause bony destruction (aggressive appearing but not malignant) typically presenting to ophthalmology due to eye symptoms.

The ethmoidal sinuses are the most frequent culprit, with destruction of the laminae papyracea resulting in a medial subperiosteal collection.

In this case the frontal sinus is the chief site of disease and the degree of bony destruction is more extreme than normal.

The patient proceeded to surgery with a subperiosteal abscess and pyocoele drained via a left frontal sinus incision.