Frontal mucocele with an accompanying orbital abscess mimicking a fronto-orbital mucocele: case report

Abstract

Background: Mucoceles are slowly expanding cystic lesions with respiratory epithelium containing mucus most commonly affecting the frontal and ethmoidal sinuses. They are caused by obstruction of sinus ostium. Mucoceles exert pressure on the bony boundaries and due to the proximity to the brain and orbit extension to these areas are common.

Case presentation: A case of a frontal mucocele with an accompanying orbital abscess mimicking a fronto-orbital mucocele is reported. A 77 year old female patient suffering from left sided proptosis and pain around the left eye was admitted to our department. She had a history of left frontal sinus mucocele one year ago that was offered an osteoplastic frontal sinus surgery that the patient refused. Patient had limitation of eye movements. Fundoscopic examination revealed a minimal papilledema. Coronal computerized tomography and orbital magnetic resonance imaging showed a frontal mucocele with suspicious erosion of the orbital roof and a superiorly localized extraconal mass displacing the orbit lateroinferiorly. Frontal and orbital masses had similar intensities. Thus surgery was planned for a fronto-orbital mucocele. During surgery no defect was found on the orbital roof. Frontal mucocele and orbital cystic mass was removed separately. Pathological examination showed a frontal mucocele and an orbital abscess wall. Postoperatively eye movements returned to normal and papilledema resolved.

Conclusion: Fronto-orbital mucoceles are commonly encountered pathologies, but frontal mucocele with an orbital abscess is a rarely seen and should be kept in mind because their treatments differ.

Figure 1

Coronal paranasal computerized tomography demonstrating a frontal mucocele and an intra orbital cystic mass having similar intensities and a suspected area of communication through the bony roof of the orbit.

Figure 2

Coronal magnetic resonance imaging demonstrating a frontal mucocele and an orbital cystic mass.

Figure 3

Axial magnetic resonance imaging demonstrating avert proptosis and lateral displacement of the orbit.

Figure 4

Microscopically, accumulation of inflammatory exudate, mucin secretion and the wall of mucocele composed of granulation tissue were seen.

Figure 5

Microscopicaly orbital abses wall is seen composed of fibrosis and inflamatory cells lacking a mucosal lining.

Figure 6

Postoperative coronal paranasal tomography demonstrating an aerating frontal sinus with a patent frontal recess that has a silicone stent in place.