From the Guidelines
Patients with osteochondroma should undergo regular surveillance with physical examination and plain radiographs of known lesions starting from birth, with consideration of dedicated MRI for lesions >5-6 cm or in the pelvis/scapula, to monitor for potential malignant transformation into chondrosarcoma. The risk of malignant transformation into chondrosarcoma in individuals with osteochondroma is estimated to be between 0.2% to 5.9% [ 1 ]. According to the surveillance recommendations for rare childhood predispositions, individuals with osteochondroma should have a physical examination every 6-12 months starting from birth, and plain radiographs of known lesions every 2-3 years [ 1 ]. Additionally, dedicated MRI should be considered for lesions >5-6 cm or in the pelvis/scapula, starting from the time of identification, with annual follow-up [ 1 ].
Key Considerations
- The majority of cases of osteochondroma are diagnosed between 3 and 5 years of age, and approximately 96% of cases develop osteochondromas before 12 years [ 1 ].
- Individuals with osteochondroma may present with reports of pain, short stature, angular deformities of long bones, scoliosis, and leg length discrepancy [ 1 ].
- Malignant transformation into chondrosarcoma is more common in males and individuals with an EXT1 PV [ 1 ].
- The incidence of transformation is higher in individuals with an EXT1 PV and more common in the pelvis/scapula [ 1 ].
Surveillance and Management
- Regular surveillance with physical examination and plain radiographs of known lesions is essential to monitor for potential malignant transformation [ 1 ].
- Dedicated MRI should be considered for lesions >5-6 cm or in the pelvis/scapula, starting from the time of identification, with annual follow-up [ 1 ].
- Pain or increasing tumor size should warrant targeted MRI of the lesion and consideration of biopsy [ 1 ].
From the Research
Definition and Characteristics of Ochondroma
- Osteochondroma is the most common benign bone tumor, characterized as a projection on the external surface of the bone, which can be sessile or pedunculated 2.
- It can present as solitary lesions (85%) or in the context of hereditary multiple exostoses (HME), a genetic disorder inherited in an autosomal dominant manner 2.
Clinical Presentation and Symptoms
- Osteochondromas are often asymptomatic, but symptoms may arise from compression of adjacent vessels or nerves, fractures, osseous deformities, bursa formation, or malignant transformation 2, 3.
- Local effects on surrounding tissues can include mechanical interaction, pressure on nearby neurovascular bundles, inflamed bursa, growth disturbances, neurological symptoms, and vascular complications 3.
Diagnosis and Treatment
- Cartilage cap thickness >2 cm in adults or >3 cm in children, new onset of pain or growth, or rapid growth of the lesion, especially after the closure of the growth plate, may indicate cancerous transformation 2.
- Surgical resection is indicated for symptomatic lesions, complications, cosmetic reasons, or malignant transformation, with excision of the tumor with a free margin being the treatment of choice 2, 3, 4, 5.
- Local recurrence is less than 2% if complete resection is achieved 2.
Management and Prognosis
- Treatment should aim not only at surgical resection of the masses but also at prevention of deformities, especially in patients with hereditary multiple osteochondroma 5.
- Effective physical therapy can enable patients to restore muscle strength and normal gait patterns after osteochondroma excision 4.