Aneurysmal bone cyst of the mandible.

The case of a 48-year-old male patient with a slowly growing mass in the right molar region of the mandible is presented. The biopsy specimen showed an aneurysmal bone cyst. After radiation therapy failed to arrest the process, the patient was treated surgically via an external approach. Between the time of the initial presentation and the date of definitive surgery 9 months later, a dramatic change was noted in the roentgenographic pattern of the lesion, demonstrating early and late stages in the development of an aneurysmal bone cyst. There has been no recurrence in a 17-year follow-up period.