Radiologic and pathologic correlation of aneurysmal bone cysts at unusual sites.

Aneurysmal bone cyst (ABC) is a benign solitary lesion. It usually occurs in the long bones but uncommonly in the calcaneum, mandible, femur and clavicle. Its frequency of occurrence in skull and mandible is 4%, clavicle and ribs is 5%, femur is 13% and foot is 3%. Only a few cases of ABC of these unusual sites have been reported till date. Here we report four cases of ABC at unusual sites namely the calcaneum, mandible, femur and clavicle diagnosed primarily on the basis of different imaging modalities and later confirmed on histopathology.