Keratocystic Odontogenic Tumor Involving the Orbital Apex
Keratocystic odontogenic tumors are an intraosseous tumor of odontogenic origin, believed to arise from dental lamina. Originally termed odontogenic keratocysts, the lesions were reclassified by the World Health Organization in 2005 due to their aggressive behavior. These tumors are known to be difficult to enucleate from bone and, if incompletely resected, often recur with aggressive, infiltrative behavior. The techniques used for resection include curettage, primary total excision, or decompression using a drain followed by complete en-bloc excision after tumor consolidation. This is a very rare tumor to implicate the orbit. This mass was discovered in an otherwise healthy 20-year-old female on routine orthodontic imaging and a CT scan was ordered to evaluate the mass (Fig. 1). Incisional biopsy was performed endoscopically through a buccal flap posterior to the right maxillary teeth. Biopsy revealed the characteristic thin, friable tumor lining of parakeratinized stratified squamous epithelium, and pathology confirmed the diagnosis of a keratocystic odontogenic tumor. Intraoperatively, the tumor lining filled the maxillary sinus and tooth #1 was firmly adherent to the orbital floor. A decision was made to leave the tooth in place to decrease the risk of communication and extension of the tumor into the orbit. The tumor sac was evacuated of a white, milky, keratinaceous-type fluid, and a drain was placed allowing the membranous sac to consolidate and the membrane to thicken. The drain was left in place for 4 months and the tumor retracted from the maxillary sinus walls and the tooth descended, releasing from the inferior orbital wall (Fig. 2). The drain was then replaced to allow for an additional 5 months of further retraction and deflation of the sac. The entirety of the tumor lining and tooth were then fully resected, again through a buccal mucoperiosteal flap using gentle curettage. The tooth and tumor were removed completely as a single entity.