Pseudo-tumoral ossification of the muscles and/or periosteum. (A study of 57 cases).

The authors present a study of fifty-seven cases of pseudo-tumoral ossification of the muscles ("circumscribed ossifying myositis") and of the periosteum, supported by clinical, radiographic and histological evidence. This pathological condition is characterised by the formation of hyperplastic bone callus in muscle or periosteum, with a typical radiographic appearance, and with a relationship to trauma. We have excluded from our study pseudo-tumoral periosteal ossification in conditions of congenital origin (osteogenesis imperfecta, neurofibromatosis, Sane et al., 1971; Kullman et al., 1972), hyperplastic fracture callus in cranial trauma, ossification of muscles in limbs which are paretic or paralysed due to cerebral or cord lesions, and hyperplastic fracture callus in congenital syphilis. The form which is the subject of this study is absolutely benign, develops over a period of twelve to twenty-four months, with spontaneous maturation and partial regression. It can abe treated by radiotherapy to accelerate maturation, or by surgery when maturation has been completed.