Dentigerous cyst presenting as orbital proptosis.

A 49-year-old man presented with an 8-week history of progressive nasal obstruction and left orbital proptosis (figure 1). On examination, his left nasal cavity was found to be obstructed by a large, hemorrhagic, polypoid mass. Computed tomography (CT) of the paranasal sinuses revealed that the 6-cm mass involved the left nasal cavity, maxillary sinus, and orbit with lateral extension into the masticator and buccal spaces (figure 2). An area of high attenuation in the posterosuperior wall of the left maxillary sinus was consistent with a displaced, unerupted tooth.

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The patient underwent endoscopic biopsy under general anesthesia. Intraoperatively, resection of the intranasal portion of the mass revealed a cystic cavity that extended into the left maxillary sinus. The left maxillary sinus was debrided of murky brown fluid and debris. The lateral nasal wall was removed endoscopically from the inferior orbital rim to the inferior turbinate to expose the lateral portion of the maxillary sinus. Further inspection revealed that the disease process had destroyed the lateral bony wall of the sinus. Also, a tooth was found to be lodged in the posterosuperior aspect of the maxillary sinus (figure 3). Postoperatively, the patient's symptoms resolved, and he deferred definitive treatment.

Dentigerous cysts, also known as follicular cysts, are associated with the crown of an unerupted or impacted tooth. They are believed to originate from the follicle of the tooth. The growth rate can be rapid, with lesions becoming as large as 5 cm in diameter in 3 to 4 years. Dentigerous cysts are most frequently found in the mandible, but they can also originate in a maxillary canine or molar.

Histologically, dentigerous cysts typically feature a thin connective-tissue wall that is lined by a thin layer of stratified squamous epithelium within the lumen. Other intracystic lesions may arise from the actual epithelial lining or from rests of odontogenic epithelium that are in the connective tissue around the cyst. Odontogenic tumors (e.g., ameloblastomas) and epidermoid carcinomas occasionally arise from the lining of the follicular cyst. Mucoepidermoid carcinomas may arise from the mucous glands within the wall of the cyst. This is the suspected origin of most intraosseous mucoepidermoid carcinomas.

Definitive treatment consists of removing the unerupted tooth and performing enucleation and curettage to prevent recurrence. Larger lesions, with sequelae from local expansion, may require early decompression to avoid serious complications.

Suggested reading

Bajaj MS, Mahindrakar A, Pushker N. Dentigerous cyst in the maxillary sinus: A rare cause of nasolacrimal obstruction. Orbit 2003;22:289-92.

Cummings CW Jr., Haughey BH, Thomas JR, et al, eds. Cummings Otolaryngology-Head and Neck Surgery. 4th ed. Philadelphia: Elsevier Mosby; 2005:1523-4.

Sofia Avitia, MD; Jason S. Hamilton, MD; Ryan F. Osborne, MD, FACS

From the Department of Otolaryngology-Head and Neck Surgery, Charles R. Drew University of Medicine and Science (Dr. Avitia); the Osborne Head and Neck Institute (Dr. Hamilton and Dr. Osborne); and the Head and Neck Cancer Center, Cedars-Sinai Medical Center (Dr. Osborne), Los Angeles.