[Desmoplastic fibroma as a rare bone tumor]

A desmoplastic fibroma of the left humerus with a pathological fracture in a 9-year-old girl is presented. The postoperative course was uncomplicated: no recidive occurred. The histological picture of this rare bone tumor (76 similar cases were reported in the literature) is identical both with aggressive fibromatosis and with the desmoid tumor. It contains areas with abundant collagen fibers and densely packed areas composed of fibrocytes, fibroblasts as well as myofibroblasts. Myofilaments have been detected by electron microscopy in the latter cell type.