Odontogenic keratocyst

There is a large well-defined lytic lesion present involving the body and angle of the mandible on the left. It measures approximately 19 x 38 mm. The lesion is very well defined and there is no break in the cortex identified.There is a retained molar tooth present in the lateral superior aspect of this cystic lesion. There is no soft tissue component identified.

DDx include a dentigerous cyst, keratocystic odontoid tumor or a unilocular ameloblastoma. CT is advised.

There is a 29 x 13 x 27 mm unilocular cystic slightly expansile lesion involving the body and angle of the left mandible, adjacent to the roots of the tooth 36 and 37 and to a lesser extent the unerupted mesially angulated 38. The lesion is not centered o the crown of 38. No dental caries or root absorption. The cortex is severely thinned inferiorly and posteriorly and there is a small region posteriorly where there is cortical breach. No periosteal reaction or pathological fracture.

The lesion extends to involve the left inferior alveolar canal near its origin.

No enlarged cervical lymph nodes.

No other destructive osseous lesion.

Small amount of bilateral maxillary sinus mucosal disease. Imaged lung apices are clear.

Conclusion

Cystic lesion of the body and angle of the left mandible. Based on location, appearances and the patients age, keratocystic odontic tumor is the favored provisional diagnosis with a differential including unilocular ameloblastoma.