What is Ollier disease

Ollier disease, also known as multiple enchondromatosis, is a rare non-hereditary skeletal disorder characterized by the development of multiple benign cartilaginous tumors, called enchondromas, that grow within the marrow space of bones. These growths primarily affect the long bones and can lead to skeletal deformities, limb length discrepancies, and an increased risk of bone fractures.

What are the primary characteristics of Ollier disease?

In Ollier disease, enchondromas typically develop during childhood. These tumors are composed of mature hyaline cartilage and most commonly affect the hands, feet, long bones (like the femur or humerus), and the pelvis. Because these tumors grow within the bone, they can disrupt normal bone growth plates, leading to asymmetry and the bowing of limbs. While the tumors themselves are benign, the primary clinical challenge for individuals with Ollier disease is managing orthopedic complications and monitoring for potential malignant transformation into chondrosarcoma, a type of bone cancer, which occurs in a subset of patients.

How common is Ollier disease and who is affected?

Ollier disease is classified as a very rare disorder, with an estimated prevalence ranging from 1 in 100,000 to 1 in 1,000,000 individuals. It is a sporadic condition, meaning it is not considered an inherited genetic disorder; there is no evidence that it is passed from parents to children. Symptoms typically manifest in early childhood, often before the age of 10. There is no significant geographic or ethnic predisposition, and both males and females are affected, though some clinical literature suggests a slight male predominance.

What causes the bone growth in Ollier disease?

The underlying mechanism of Ollier disease involves somatic mosaic mutations in the IDH1 or IDH2 genes. These mutations occur post-fertilization, meaning they are present only in certain cells of the body rather than in every cell. This genetic "mosaicism" explains why the condition is not hereditary. These mutations cause the bone-forming cells to produce disorganized cartilage, resulting in the characteristic enchondromas that define Ollier disease.

Key clinical features and differences

It is important to distinguish Ollier disease from Maffucci syndrome. While both involve multiple enchondromas, Maffucci syndrome is characterized by the additional presence of soft tissue hemangiomas (vascular malformations). Key clinical aspects of Ollier disease include:

• Asymmetric distribution: Enchondromas are often more severe on one side of the body.


• Limb length discrepancy: Uneven bone growth often requires orthopedic intervention.


• Pathological fractures: Bones weakened by internal tumors are more prone to breaking.


• Malignancy risk: Lifelong monitoring is required because of the risk of developing chondrosarcoma, which occurs in approximately 25-30% of patients over their lifetime.

Our community at DiseaseMaps.org currently supports 279 members who are living with or caring for someone with Ollier disease, providing a space for shared experiences and peer support.

Next steps

• Consult an orthopedic oncologist to establish a baseline and long-term monitoring plan for your bone health.


• Request regular skeletal surveys or MRI imaging as recommended by your specialist to track tumor growth.


• Join a patient support group or the DiseaseMaps community to connect with others navigating similar treatment paths.


• Maintain a log of any new pain or localized swelling, as these symptoms should be evaluated promptly by a medical professional.

Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Ollier Disease Overview


• Orphanet: Multiple Enchondromatosis (Ollier disease)


• OMIM (Online Mendelian Inheritance in Man): Enchondromatosis; ENCH