A Calcifying Odontogenic Cyst With Compound Odontoma in the Maxillary Sinus: A Case Report in a Pediatric Patient.

Calcifying odontogenic cysts (COCs) exhibit a diverse clinical course, commonly developing between the second and third decades of life, displaying no gender predilection. A 15-year-old female without medical history was under observation for a mixed lesion in the maxilla associated with an impacted tooth. She presented to the emergency department with sudden onset and worsening swelling of the left midface. Radiographic findings in the panoramic radiograph and a CT scan revealed a well-circumscribed mixed lesion localized in the left maxilla, extending into the left maxillary sinus and reaching the orbital floor. After an intercurrent infection of the cyst, the patient was hospitalized, received intravenous antibiotics, and went for surgical intervention under general anesthesia. Lesions that combine histological characteristics of two or more odontogenic tumors or individual cysts in the same location are called hybrid odontogenic lesions. This type of lesion poses a challenge for both pathologists and surgeons, because of its controversial histogenesis and poorly understood clinical evolution. The most common of these lesions are COCs associated with odontoma. Our case represents an exceptionally rare entity among odontogenic cysts.