Expansile bone lesion

Aneurysmal bone cyst, abbreviated ABC, is an osteolytic bone neoplasm characterized by several sponge-like blood or serum filled, generally non-endothelialized spaces of various diameters.The term is a misnomer, as the lesion is neither an aneurysm nor a cyst. Signs and symptoms The afflicted may have relatively small amounts of pain that will quickly increase in severity over a time period of 6–12 weeks. [Source: Wikipedia ]