Aneurysmal bone cyst of the jaws. (I). Clinicopathological features.

A clinicopathological study has been performed on a series of 42 well-documented examples of aneurysmal bone cyst of the jaws recorded in the literature, and 4 additional personally observed cases. Most occurred in the first three decades (93%), 2/3 of patients being younger than 20 years. There was a preponderance of females (62%). Both mandible and maxilla were involved, particularly the molar regions. A number of mandibular cases extended to the angle and ascending ramus. Swelling was usually present and there was frequently a history of rapid growth. Radiologically, they often appeared as multilocular radiolucencies with expansion and thinning of the cortical plates. Histologically, the lesions consisted of multiple cystic spaces of varying size, usually filled with blood. The intervening solid tissue frequently showed features of other pathological lesions, particularly the central giant cell granuloma, but occasionally as fibrous dysplasia, ossifying fibroma and cementifying fibroma. Recurrences have been common probably because of technical difficulties in entirely removing very large lesions. Thorough curettage, if necessary by an extraoral approach, is the most favoured method of treatment.