A case of orbital emphysema associated with frontal sinus pneumocele

Abstract

Orbital emphysema is usually caused by trauma and fracture of an orbital bone, allowing air to pass from the sinuses into the orbit. Orbital emphysema without any significant trauma is rare. We present a case of a 67-year-old-woman who complained of left exophthalmos without any history of trauma, sneezing, or sinus surgery. Computed tomography scanning showed left orbital emphysema protruding the eyeball forward. The left frontal sinus was remarkably enlarged associated with a partial defect of the orbital roof, allowing air entry into the orbit. In addition, the frontal sinus ostium was occluded with the mucocele that served as a one-way valve between the frontal and the ethmoidal sinuses. We performed frontal craniotomy and removed the mucocele and the inner table of frontal bone to communicate the frontal sinus with the nasal cavity. After operation, her exophthalmos was improved.

Keywords: frontal sinus pneumocele; orbital emphysema; transcranial surgery.

Fig. 1

(A) Left exophthalmos, 15 mm on the right and 22 mm on the left by Hertel exophthalmometry. Axial imaging of computed tomography (B, C) showing left frontal sinus pneumocele and orbital emphysema protruding the eye ball forward. Coronal imaging (D) showing that the left frontal sinus was remarkably enlarged and the orbital roof was partially absent. The frontal sinus ostium was occluded with the mucocele that served a one-way valve between the frontal and the ethmoidal sinuses.

Fig. 2

Surgical view showing that the periorbita was observed through the bony defect (black arrow). After removal of mucus as well as the frontal sinus mucosa, the sinus ostium was enlarged by drilling the surrounding bone to fully open a blockage of the communication of the frontal sinus with the nasal cavity (white arrow).

Fig. 3

(A, B) Computed tomography scans and (C) picture after operation showing removal of orbital emphysema and improvement of left exophthalmos.