CASE REPORT
A 29-year-old male presented with a one-month history of left cheek pain and a two-week history of left cheek swelling. He had a history of diabetes and was receiving hypoglycemic medication. His mother died of gastric cancer, and his aunt had a history of total colectomy. An endoscopic examination revealed an elevated anterior nasal floor and closed inferior meatus bilaterally (Fig. 1). Mucopurulent discharge was noted in the left middle meatus.
Intraoral examination revealed multiple caries and tooth defects (Fig. 2). Computed tomography showed nodular osteosclerosis of the maxilla and mandible (Fig. 3a, b) and multiple impacted maxillary teeth. Soft tissue shadows and bone erosion were observed around the upper left impacted tooth. Additionally, the soft tissue shadow around the impacted tooth was continuous with the left maxillary sinus (Fig. 3c, d). Multiple osteomas were found in the ethmoid sinus, frontal sinus, and skull (Fig. 4). We diagnosed the patient with left odontogenic maxillary sinusitis.
GS was suspected due to the positive family history, multiple osteomas of the skull and facial bone, and abnormal teeth. Multiple adenomas were found in the stomach and colon (Fig. 5) on gastrointestinal endoscopy. Furthermore, genetic testing revealed a mutation in the adenomatous polyposis coli (APC ) gene, leading to a diagnosis of GS. Sinusitis improved following tooth extraction and macrolide therapy for three months. Prophylactic colectomy has been planned for FAP.