The cause of intraosseous lipoma of the calcaneus is unknown.Three theories have been proposed (1,10). The first is that the tumormight be a posttraumatic bone reaction. However, in a study of 49cases, only 5 had a history of trauma (7,21). The second theory is thehealing of bone infarct theory. This theory is not widely acceptedbecause bone infarcts on the calcaneus occur mostly in the posteriorregion, not in Ward’s triangle, which is localized anteriorly. Furthermore, bone infarcts cannot expand the bone (22). The third and mostaccepted theory is that this is a true benign tumor