Calcaneal cysts. A radiological and anatomico-pathological study.

A radiological and anatomico-pathological study of 17 cases of calcaneal cysts in young patients without other known affections is documented. There are two essential histological characteristics of the fibrous wall lining the cysts: (1) hemosiderin deposits together with cholesterol and an associated giant cell reaction, which can be attributed to previous hemorrhages; (2) newly formed bone--similar to that observed in solitary cysts of the humerus and femur--applied to preexisting trabeculae which forms a bony wall explaining the typical radiological picture. These uncommon cysts may be the evolution of purely local hemorrhages in the trigonum calcis.