Pneumocele is a rare condition produced by extensive expansion of maxillary sinus and thinning of the bony walls. It may cause displacement of neighboring structures. This lesion may remain asymptomatic over long periods and rarely presents with classic signs. We present a rare case of maxillary pneumocele presenting with severe deep orbital pain.

A ten year old boy presented with progressive left orbital pain for 9 months. The center of pain was deep orbit. He also experienced two episodes of severe orbital pain with barotrauma during descent in travels to the mountainous regions. The parents also had noted swelling of the left cheek since two years ago.

The patient underwent functional endoscopic surgery based on the presumed etiology of occlusion of the sinus ostium by one-way valve mechanism. There was significant improvement of symptoms after surgery.

Most pneumoceles remain asymptomatic over long periods and are not diagnosed until there is an external deformity or the displacement of adjacent structures causing symptoms. Treatment is based on relieving one-way valve mechanism as we reported in our case.