We report two cases of mucocele formation after medial orbital wall fracture repair with an alloplastic implant.

A 61-year-old man with a history of a medial orbital wall fracture repaired with an alloplastic implant five years earlier presented with a several-month history of left proptosis without diplopia, pain, or lid edema. A 55-year-old man with a history of a medial orbital wall fracture repaired with an alloplastic implant seven years prior, presented with a five.year history of left proptosis with diplopia. Computed tomography (CT) scans revealed a large cyst on the orbital medial wall, which surrounded the alloplastic implant and had no definite enhancement. The patients underwent orbital surgery to remove both the cyst and implant. Histologic examination of the cyst revealed a capsule lined with ciliated pseudostratified columnar epithelium. Both patients had an uncomplicated postoperative course with resolution of the proptosis.

For cases that present with late proptosis after orbital fracture repair, mucocele formation should be included in the differential diagnosis.