bubble_chart Overview

Dyschondroplasia, also known as enchondromatosis, Ollier's disease, etc., is characterized by round or columnar cartilaginous masses at the metaphysis of long bones, accompanied by shortening and deformity of the bone shaft, particularly common in the phalanges. First described by Ollier in 1899, although its tissue structure is similar to that of enchondroma, it is generally believed that this disease should not be classified within the scope of tumors.

bubble_chart Etiology

The cause of the disease is unknown. It is a congenital developmental malformation with no hereditary or familial history. Some believe that chondroblasts remaining in the bones during the embryonic period may not mature normally. As the bones grow, these cells remain in the metaphysis and retain their proliferative capacity. Under appropriate conditions, they develop into cartilaginous masses or cartilage columns. This disease is rare, with a slightly higher incidence in males than in females, and typically manifests during childhood or adolescence.

bubble_chart Pathological Changes

Under the microscope, numerous cartilage cell masses can be seen within the transparent matrix, ranging from small chondroblasts to larger, more mature vacuolated chondrocytes, arranged in disorderly clusters. There are fibrous septa and areas of mucoid degeneration. Additionally, there are patchy and punctate deposits of calcium salts. Microscopically, this condition is indistinguishable from an endochondral bone tumor.

bubble_chart Clinical Manifestations

At birth, there are generally no abnormal manifestations. The disease onset occurs during the growth period, predominantly affecting the metaphysis of long bones that are actively growing, such as the areas around the knee joint, the distal ends of the radius and ulna, and the proximal end of the humerus. The hand, particularly the phalanges, is the most common site. In the pelvis, it frequently occurs at the iliac crest. The elbow joint is less commonly affected. Due to asymmetrical growth of the epiphysis, limb shortening occurs, accompanied by varus or valgus deformities. The radius becomes long and curved, leading to dislocation of the radial head. Soft bone tumors in the fingers can grow large and numerous, completely impairing hand function. Pathological fractures are rare in areas other than the phalanges.

X-ray findings: In the metaphysis, there are variably sized, irregularly shaped, well-defined areas of chondrification arranged in columns, appearing striated on X-rays. The metaphysis shows irregular expansion, thickening and shortening of the diaphysis, and bending, with adjacent epiphyses appearing speckled. In the phalanges, there are enlarged, irregular cystic lucent areas interspersed with dense calcified streaks and spots, causing deformation of the phalanges. In the ilium, cartilage columns radiate fan-like towards the iliac crest. By adolescence, the cartilage cell columns are no longer visible and are replaced by dense spots, indicating a tendency towards healing.

bubble_chart Diagnosis

If diagnosed based on a single localized lesion, it is difficult to differentiate from an endochondroma; however, a comprehensive examination makes the diagnosis straightforward. For suspicious cases, X-rays of both hands are often helpful. The diagnostic criteria are as follows: ① Onset in early childhood. ② Multiple lesions, mostly occurring at the ends of long bones. ③ Radiographically lucent areas with biopsy showing cartilage tissue.

bubble_chart Treatment Measures

For masses that severely affect function, surgical removal can be performed. To address limb length discrepancy, limb lengthening surgery, epiphyseal arrest, or osteotomy can be performed to correct varus or valgus deformities. Bone healing after osteotomy is normal.

bubble_chart Prognosis

The prognosis of this disease is favorable and does not affect life expectancy. The malignant transformation rate of soft bone tumor-like masses is 1-5%. If sudden enlargement or pain occurs, malignancy should be suspected, and the treatment principles are the same as for soft osteosarcoma.

bubble_chart Differentiation

Sometimes it is necessary to differentiate from the following diseases: ① Diaphyseal aclasis: It has obvious heredity, manifested as multiple exostoses, and the metaphysis is enlarged like a trumpet. ② Osteopoikilosis (bone spotting disease): Bone spots are widely distributed throughout the body, the bone structure is normal, and there are no enchondromatous masses. ③ Fibrous dysplasia: Although it is a cystic sexually transmitted disease, it often occurs in the diaphysis and skull, with unclear edges, and is often accompanied by diffuse osteosclerosis.