Keratocystic Odontogenic Tumor with an Ectopic Tooth in Maxilla

The term odontogenic keratocyst was first used by Philipsen in the year 1956. The lesion was renamed by him as keratocystic odontogenic tumor (KCOT) and reclassified as odontogenic neoplasm in the World Health Organization’s 2005 edition that occurs commonly in the jaws having a predilection for the angle and ascending ramus of mandible. In contrast, KCOTs arising in the maxillary premolar region are relatively rare. Here, we discuss a rare case of keratocystic odontogenic tumor occurring in the maxilla with an ectopic tooth position. 1. Introduction Keratocystic odontogenic tumor (KCOT) is defined as “a benign uni- or multicystic, intraosseous tumor of odontogenic origin, with a characteristic lining of parakeratinized stratified squamous epithelium and potential for aggressive, infiltrative behavior.” In 2005, the World Health Organization redefined the odontogenic keratocyst as a result of its biological behavior as a benign tumor of odontogenic origin and named it as keratocystic odontogenic tumor. KCOTs comprise approximately 11% of all cysts of the jaws. They occur most commonly in the mandible, especially in the posterior body and ramus regions. They almost always occur within bone, although a small number of cases of peripheral KCOT have been reported. 2. Case Report A 17-year-old male patient came to the department with a chief complain of pus discharge from the right upper back teeth region 3-4 months ago with pain and swelling 15？20 days ago. Pain was gradual in onset, throbbing type, continuous, nonradiating, aggravates on mastication, and relieved on taking medication. Swelling was initially smaller in size and gradually increased to the present size associated with pus discharge from right upper back region 2-3 months ago. There was no history of trauma or fever. Patient also gave history of exfoliation of a tooth from right upper back tooth region on its own (Figure 1). Figure 1: Profile photograph of the patient. On general physical examination, patient was found to be moderately built and nourished. He was conscious, cooperative, and well oriented with time, place, and person. Extraoral examination showed no abnormality. On intraoral examination, a localized, solitary swelling was present in the right upper back vestibular region measuring approximately 1–1.5？cm in diameter in relation to teeth 15, 16 with overlying mucosa slightly erythematous in appearance; however the surface appeared to be smooth and the surrounding area appeared normal. On palpations all inspectory findings were confirmed. The swelling was nontender, bony hard in