Giant keratocystic odontogenic tumor invading bilateral maxillary sinuses

Keratocystic odontogenic tumors (KCOT) are highly proliferative and have a high recurrence rate. Therefore, this disease is categorized as a benign tumor, not merely a cyst in the jaw. In general, KCOT are more frequent in the mandible than the maxilla, and rarely advance locally into the maxillary sinus. In addition, it is extremely rare for giant unilocular KCOT to invade the bilateral maxillary sinuses and inferior nasal meatus. In this study, we describe the case of a giant unilocular KCOT that had advanced into the bilateral maxillary sinuses and inferior nasal meatus. A 40-year-old female presented at our hospital with swelling of the left cheek. Computed tomography showed a benign tumor that filled the bilateral maxillary sinuses and was compressing and absorbing the inferior nasal meatus. The clinical diagnosis was a maxillary odontogenic benign tumor, such as a calcifying cystic odontogenic tumor. A biopsy was performed and the pathology examination revealed a diagnosis of KCOT. In determining the treatment plan, cosmetic considerations were required. We performed marsupialization and observed shrinkage of the tumor, in line with previous reports. We then performed enucleation under the guidance of a rigid endoscope through the oral cavity. To date, there has been no recurrence and the progress is good. However, this disease has a high recurrence rate and must be carefully observed.