Camurati-Engelmann disease

Camurati-Engelmann disease (CED), or progressive diaphyseal dysplasia, is a rare sclerosing dysplasia of which 250 cases have been described in the English literature. The disease affects one in a million people and is autosomal dominant with variable penetrance. It was initially described by Cockayne in 1920; Camurati was the first to suggest its hereditary nature in 1922. A single case of muscular wasting and marked bone involvement was reported by Engelmann in 1929. As the name suggests, there is progressive hyperostosis and predominant involvement of the diaphyses. The onset of the disease is usually during childhood; patients usually present by puberty and usually before age 30, with limb pain, muscular weakness, waddling gait and easy fatigue. Other symptoms and signs may include delayed growth, reduced muscle mass, anorexia and enlargement of the arms and legs. Systemic manifestations of hepatosplenomegaly, bone marrow dysfunction (anaemia and leucopaenia) and delayed sexual development occasionally occur. In a few patients, abnormal values of bone resorption and formation have been described. Radiologically, the hallmark of the disorder is bilateral, symmetrical cortical thickening of the diaphyses of the long bones on both the periosteal and endosteal sides of the diaphyses. In decreasing order of frequency, the tibia, femur, fibula, humerus, ulna and radius are affected. CED results from disturbance of intramembranous ossification (Fig.1) affecting the long bones, calvaria, mandible and facial bones. There are a few reported cases of involvement of the skull base (a site of endochondral ossification), but these occur in advanced stages.