Aneurysmal Bone Cyst
Etiology: Considered a pseudocyst, in that it appears as a cyst, but unlike the epithelium-lined true cyst, the aneurysmal bone cyst does not have the epithelium-lined lumen.
Epidemiology: Found in individuals less than 30 years of age, with a peak incidence in the second decade of life.
Pathogenesis: Unclear about whether there is a preexisting lesion or whether the bone cyst develops because of dilated vessels.
Extraoral characteristics: Extraoral swelling is reported in extensive lesions.
Perioral and intraoral characteristics: Swelling without pain. Radiographic features of an aneurysmal bone cyst include a unilocular or mulitlocular lesion, described as having a soap bubble appearance. Thinning and expansion of the cortical bone may be seen. Ballooning and distention of the cortical bone is often recognized.
Distinguishing characteristics: Exhibit some key radiographic appearances. The lesion presents as expansile, with thin peripheral bone that is blood filled, without the presents as expansile, with thin peripheral bone that is blood filled, without the presence of what is called bruit, thrill, or pulse pressure.
Significant microscopic features: Composed of immature connective tissue and scattered multinucleate giant cells.
Dental implications: May cause the teeth to become displaced or loose because of bone expansion.
Differential diagnosis: Odontogenic keratocyst, central giant cell granuloma, ameloblastic fibroma, and ameloblastoma.
Treatment and prognosis: Excision and curettage are treatments of choice. When the lesion is removed completely, the prognosis is good.
Oral medicine consideration: Questions to ask patient when assessing the condition.