The radiological features of "solid" aneurysmal bone cysts.

The radiological features of nine solid aneurysmal bone cysts (ABC) have been reviewed. The appearances form a spectrum ranging from lesions indistinguishable from the classical ABC, to an osteolytic lesion with a wide zone of transition, cortical destruction and soft tissue extension. Over half the lesions reviewed fell into the latter category and all were situated in the axial skeleton. Discrimination between the more aggressive solid ABC, giant cell tumour and malignancy may be difficult. Demonstration of an expanded partial cortical rim by either conventional or computerised tomography suggests the diagnosis of solid aneurysmal bone cyst.