Maxillary sinus mucocele is an uncommon benign lesion that develops due to retained secretions and presents as an expansile cystic lesion. Patient presents with non-specific symptoms and are mostly due to pressure effects on the orbit or palate causing facial deformity. Etiology is not well established, and it is proposed that they ensue due to obstruction of the ostium by inflammation or previous procedures. De novo origins result in unwanted investigations and delayed diagnosis and treatment. Endoscopic marsupialization of the mucocele, middle meatal antrostomy with maxillary sinus clearance or inferior meatal antrostomy are the surgeries of choice. Here is a case of left maxillary mucocele which had no identifiable cause, and is reported due to its rare incidence and delayed management.

Keywords: Mucocele; Maxillary sinus; Middle meatal antrostomy