From the Guidelines
Enchondroma arises from hyaline cartilage, not from tendons, as it develops within the medullary cavity of bones, originating from remnants of growth plate cartilage that become entrapped during skeletal development. This is supported by the most recent study 1, which describes enchondromas as benign, cartilaginous neoplasms that arise from the medullary cavity of bones and cause bone expansion. The study further explains that enchondromas typically grow to sizes up to 3 cm and do not cause pain, highlighting their benign nature.
Key Characteristics of Enchondromas
- They are composed of hyaline cartilage cells that failed to undergo normal ossification during bone formation
- They most commonly affect the short and long tubular bones of the limbs, but can also involve the axial skeleton
- They are often found in the small bones of the hands and feet, as well as long tubular bones like the femur and humerus
- They typically remain asymptomatic and are often discovered incidentally on imaging studies performed for other reasons
Histological and Radiographic Appearance
- Enchondromas are characterized histologically by lobules of hyaline cartilage with low cellularity and minimal atypia
- They have a radiographic appearance as well-defined lucent lesions with internal calcifications
- Understanding their origin from hyaline cartilage explains their potential for malignant transformation to chondrosarcoma in certain cases, particularly in multiple enchondromatosis syndromes, as noted in the study 1
Clinical Implications
- The study 1 highlights the importance of considering alternate diagnoses, such as HMOs, metachondromatosis, spondyloenchondrodysplasia with immune dysregulation, and metaphyseal enchondromatosis with D-2-hydroxyglutaric aciduria, when assessing individuals with enchondromas
- Malignant transformation of enchondromas to chondrosarcoma is a notable concern, occurring in about 30% of patients, and can happen in any bone, with the sites with the highest rates including the femur, tibia, humerus, pelvis, and scapula 1
From the Research
Enchondroma Origin
- Enchondroma is a benign tumor that arises from the medullary cavity of bone, composed of mature hyaline cartilage 2, 3, 4, 5.
- There is no evidence to suggest that enchondroma arises from tendons, with all studies indicating its origin in hyaline cartilage within the bone 2, 3, 4, 5.
Composition and Characteristics
- Enchondromas are characterized by their composition of mature hyaline cartilage with typical chondrocytes 3.
- They have a predilection for the ulnar-sided tubular bones of the hand and can occur in other locations such as the spine, although this is rare 2, 3.