Type III frontal recess air cell as a cause of frontal sinus pneumocele has not been previously reported in literature. A 31-year-old woman with chronic history of sinusitis presented with pressure in the left eye on blowing the nose. Computed tomography examination of the orbits and paranasal sinuses with coronal and sagittal reformatted images showed abnormal collection of gas in the soft tissues at the superior aspect of the left orbit contiguous with the overlying left frontal sinus through a large defect in the orbital roof and a type III frontal recess air cell narrowing the left frontal recess.
