Known as Engelmann's disease, diaphyseal sclerosis, and Camurati-Engelmann-Ribbing disease, it is characterized by symmetrical spindle-shaped enlargement and sclerosis of the long bone diaphyses. This rare condition is slightly more common in males than females, with an average onset age of 19.2 years, ranging from 3 months to 57 years. The long bones affected, in order of frequency, are the tibia, femur, fibula, humerus, ulna, and radius, with bones of the hands and feet being less commonly involved. The skull is also a common site of occurrence.

bubble_chart Etiology

Unclear, considered as congenital developmental anomaly, autosomal dominant inheritance.

bubble_chart Pathological Changes

Osteosclerosis, with thickening and coarsening of trabeculae, increased fibrous tissue within the bone membrane, a tendency for the cortical bone to transform from compact to spongy bone, and the medullary cavity being filled with adipose and fibrous tissue.

bubble_chart Clinical Manifestations

The child has delayed tooth eruption, late and unsteady walking, with a characteristic waddling gait. As the condition progresses, leg pain and headache develop and gradually worsen. Thickened long bone shafts can be palpated. The patient is prone to lack of strength, emaciation, dryness, and shows signs of malnutrition. The head is enlarged with a prominent forehead. Due to hyperplasia and sclerosis of the skull base bone plate, cranial nerves can be compressed, leading to symptoms such as eye atrophy and deafness. Due to the reduction in the bone marrow cavity, hematopoietic dysfunction occurs, causing compensatory enlargement of the liver and spleen.

X-ray findings: The long bone shafts are spindle-shaped and thickened, with thickened cortex (both internally and externally), and a reduced medullary cavity, usually not involving the epiphysis. The skull base is sclerotic. The disease is characterized by being bilateral, symmetrical, and systemic (Figure 1, Figure 2).

Figure 1 Progressive diaphyseal dysplasia

Figure 2 Schematic X-ray of osteopathia striata

bubble_chart Auxiliary Examination

Laboratory tests are generally normal, with occasional cases showing elevated AKP.

bubble_chart Diagnosis

The differential diagnosis should primarily distinguish it from infantile cortical hyperostosis (Caffey's disease) based on X-ray findings. This condition occurs within the first year of life, often before 6 months, and is accompanied by fever. The affected bones are usually unilateral and may involve the mandible, with rapid recovery thereafter. X-ray findings are completely normal. When a single long bone is involved (rare), it may sometimes need to be differentiated from osteomyelitis and bone syphilis.

bubble_chart Treatment Measures

There is no specific treatment, and some believe that hormones can alleviate symptoms.

bubble_chart Prognosis

The prognosis is generally good, but in severe cases, increased intracranial pressure and compression of cranial nerves can lead to headaches, hearing loss, decreased sense of smell, eye atrophy, deviation of the mouth, and other symptoms. This condition does not affect growth or the life process.