Ollier disease

Ollier disease is a rare nonhereditary sporadic disorder where intraosseous benign cartilaginous tumors (enchondroma) develop close to growth plate cartilage. Prevalence is estimated at around 1 in 100,000.

Presentation

Nominally, the disease consists of multiple enchondromas which usually develop in childhood. The growth of these enchondromas usually stops after skeletal maturation. The affected extremity is shortened (asymmetric dwarfism) and sometimes bowed due to epiphyseal fusion anomalies. Persons with Ollier disease are prone to breaking bones and normally have swollen, aching limbs.

Associated conditions

Ollier disease carries a high risk of skeletal, visceral and brain malignancy which occurs in approximately 25% of patients. Juvenile granulosa cell tumour has been associated with the disease. The incidence of secondary chondrosarcoma in Ollier disease is not known, but may be as high as 25%, pelvis and shoulder girdle being the commonest locations. A related disorder called Maffucci syndrome named after Angelo Maffucci is characterized by enchondromas associated with multiple hemangiomas which usually occur in the hands and feet. Maffucci syndrome carries a higher risk for cancer. Epidemiology Ollier disease is estimated to occur in 1 in 100,000 people.

Cause

• In most people with Ollier disease, the disorder is caused by mutations in the IDH1 or IDH2 gene.
• These genes provide instructions for making enzymes called isocitrate dehydrogenase 1 and isocitrate dehydrogenase 2, respectively.
• These enzymes convert a compound called isocitrate to another compound called 2-ketoglutarate.
• This reaction also produces a molecule called NADPH, which is necessary for many cellular processes.

Gene mutations

• IDH1 or IDH2 gene mutations cause the enzyme produced from the respective gene to take on a new, abnormal function.
• Although these mutations have been found in some cells of enchondromas in people with Ollier disease, the relationship between the mutations and the signs and symptoms of the disorder is not well understood.
• Mutations in other genes may also account for some cases of Ollier disease.

Inheritance

• Ollier disease is not inherited.
• The mutations that cause this disorder are somatic, which means they occur during a person's lifetime.
• A somatic mutation occurs in a single cell.
• As that cell continues to grow and divide, the cells derived from it also have the same mutation.
• In Ollier disease, the mutation is thought to occur in a cell during early development before birth; cells that arise from that abnormal cell have the mutation, while the body's other cells do not. This situation is called mosaicism.

Diagnosis

• Ollier disease is typically diagnosed based on a clinical examination that matches symptoms of Ollier disease.
• This exam might include using CT scans, MRIs, or X-rays to view the bones more clearly.
• Biopsies of the enchondromas are also used to look for features that are characteristic of Ollier disease.
• On radiographs, streaks of low density are seen projecting through the diaphyses into the epiphyses of the long bones, due to ectopic cartilage deposits. With age, the cartilage may calcify in the typical "snowflake" pattern.

Treatment

• The deformities are managed surgically to preserve the function of the limb.
• Treatment for Ollier disease depends on how much the enchondromas are impacting the physical abilities of the affected individual.
• In some cases, surgery or joint replacement might be an option to correct some of the enchondromas.
• However, sometimes surgery causes more enchondromas to develop, so doctors may choose to perform surgery only if absolutely necessary.
• Other treatment options include physical therapy.
• The goals of treatment are to relieve any pain caused by the enchondromas and to allow the affected individual to walk with a normal gait.

Epidemiology

One person in every 100,000 is affected. Ollier disease is not normally diagnosed until toddler years because it is not very visible. More research is needed in the genetics of this disease. Currently the literature says it is not hereditary, however, rarely it can be found in some families as far as the fourth generation.

Eponyms

The disorder is named after French surgeon Louis Léopold Ollier.

Additional images

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  X-ray showing calcified enchondromas localized in finger a 37-year-old patient affected with Ollier disease

• X-ray showing enchondromas localized in the humerus of a 37-year-old patient affected with Ollier disease

• 

  X-ray showing enchondromas localized in the lower part of the radius of a 37-year-old patient affected with Ollier disease

• MRI showing enchondromas localized in the lower part of the radius of a 37-year-old patient affected with Ollier disease

• MRI showing enchondromas localized in the lower part of the radius of a 37-year-old patient affected with Ollier disease.

• 

  Enchondromas localized in the upper part of the humerus of the same patient

See also

• Maffucci syndrome
• Chondrosarcoma

External links

Classification	ICD-10: Q78.4 ICD-9-CM: 756.4 OMIM: 166000 MeSH: D004687 DiseasesDB: 9212
External resources	eMedicine: radio/247