Rationale: A postoperative maxillary mucocele (POMM) is a delayed complication of maxillary sinus surgery. Although transoral enucleation is a conventional approach for its treatment, the intraoperative risk of injury to the inferior rectus muscle increases when there is an orbital floor defect. The transnasal endoscopic marsupialization has also been used widely for treatment. However, it has a potential risk of postoperative stenosis of the meatal antrostomy site, especially when the medial wall of the maxillary sinus is thick.
Patient concerns: A 60-year-old man who underwent a right Caldwell-Luc operation about 30 years ago came to the emergency room with pain and swelling in the right periorbital region.
Diagnosis: He was diagnosed with a POMM accompanied by an orbital floor defect and a thick medial wall of the maxillary sinus.
Interventions: Transnasal endoscopic marsupialization was performed, and a cylindrical penrose drain was placed at the antrostomy site for one month.
Outcomes: The patient's periorbital pain disappeared after surgery. After 3 months, the postoperative computed tomography scan showed good opening at the meatal antrostomy site.
Lessons: In a patient with POMM with an orbital floor defect and a thick medial wall of the maxillary sinus, transnasal endoscopic marsupialization with penrose drain insertion could prevent both injury of the inferior rectus muscle and postoperative stenosis.