A 36-year-old man presented because of nasal obstruction, rhinorrhea, and postnasal drip. The patient had undergone reconstruction of a blow-out fracture of the orbital floor 12 years before and had sinusitis that likely had resulted from implant migration into the maxillary sinus. The inflammation was successfully resolved, and the implant was removed through a minimally invasive endoscopic sinus surgery technique. On pathologic examination, an organizing hematoma was identified as the cause of the lesion. Pre- and postoperational paranasal sinus computed tomography images were taken to compare the anatomy of the sinus before and following surgery.