Clinical Pathologic Conference Case: A Radiolucency with Mild Swelling of the Right Mandible
Periapical radiograph showing relatively well-defined unilocular radiolucency. ABSTRACTS OOOO e134 April 2021 Clinical Presentation: A 58-year-old female presented with an asymptomatic mild buccal cortical expansion between teeth #29 and #30. Her medical history was unremarkable. A periapical x-ray, panoramic radiograph, and computed tomography scan were taken (Figures 1-3). Upon surgical excision, a solid mass was removed and submitted for microscopic examination. Differential Diagnosis: After reviewing the clinical and radiographic features, this disease process is likely benign. The radiographs exhibit a well-circumscribed, unilocular radiolucency; disruption of the overlying alveolar bone; and resorption of the buccal cortical plate. The differential diagnoses include central odontogenic fibroma, lateral periodontal cyst, ameloblastoma, squamous odontogenic tumor, and cemento-ossifying fibroma. Central odontogenic fibroma (COF) is a benign tumor that is more commonly found in the posterior mandible, but it can also be seen in the anterior maxilla. Clinically, it presents as a nontender swelling and painless expansion of the cortical bone. Radiographically, central odontogenic fibromas may be unilocular or multilocular radiolucencies. Occasionally, some of the lesions have a mixed radiopaque/radiolucent appearance. A wide age range of patients can be affected. COF has a slight predilection for female patients.1 COF is the top differential diagnosis because the patient is a female with a radiolucent, painless, and slightly expansile lesion of the posterior mandible. Grossly, COF is a benign and solid mass, much like the lesion in this case. Lateral periodontal cyst (LPC) is an asymptomatic odontogenic cyst commonly seen in the premolar, canine, and lateral incisor regions of the mandible. Most LPCs occur in the fifth to seventh decades of life and have a male predilection. Radiographically, LPC usually presents as a well-circumscribed, unilocular radiolucency adjacent to a vital tooth.2 LPC is in the differential diagnosis because it is consistent with the clinical and radiographic presentation of this case. The patient falls in the correct age range. She had an asymptomatic, radiolucent lesion that was located adjacent to a vital premolar. However, the gross specimen in this case was described as a solid mass, whereas an LPC would have a cystic appearance.