Metachondromatosis: more than just multiple osteochondromas

Area of Science:

• Genetics
• Orthopedics
• Rare Diseases

Background:

• Metachondromatosis is a rare genetic disorder characterized by osteochondroma and enchondroma formation, linked to PTPN11 gene mutations.
• Distinctive features include lesion distribution (hands, feet, femora, tibiae, pelvis) and inheritance patterns, differentiating it from similar conditions.
• Lesions are typically noted to regress in adulthood.

Purpose of the Study:

• To review current literature on metachondromatosis.
• To present four new cases within a family affected by metachondromatosis.
• To analyze the natural history, complications, and management of metachondromatosis.

Main Methods:

• Comprehensive literature review on metachondromatosis.
• Clinical presentation and follow-up of four new family cases.
• Analysis of histopathological findings and long-term outcomes.

Main Results:

• Long-term follow-up confirms spontaneous regression of lesions by skeletal maturity.
• Potential complications include nerve palsy, avascular necrosis of the femoral head, and angular deformities.
• Histopathology reveals a mix of osteochondromas and enchondromas, with one reported chondrosarcoma case.

Conclusions:

• Metachondromatosis lesions can cause complications but are often asymptomatic or cause cosmetic concerns.
• The majority of lesions regress spontaneously, suggesting conservative management is often appropriate.
• Regular clinical review and selective imaging are recommended to monitor for complications; surgery is typically reserved for complicated cases.