Enchondroma is a benign cartilage forming tumor.
- Commonly occurs in childhood, but not recognized until 20- 30 years of life due to asymptomatic nature.
- Men and women are equally affected.
- They are located in the Diaphysis, Metaphysis and rarely epiphysis of short bones of hand, feet and long bones of limbs.
- Etiology of enchondroma is unknown.
- Familial patterns with multiple family members are affected rarely.
- Multiple enchondromas are associated with syndromes such as Ollier’s Disease (Non Hereditary), Maffucci’s Syndrome (Hemangioma of soft tissues).
- Multiple enchondromatosis may result in deformity of the involved bone.
- Risk of malignant transformation is less/rare (less than 1%) for multiple enchondromas.
The true incidence of enchondromas are rare since most enchondromas are asymptomatic and are not detected.
How is enchondroma identified?
- Most individuals have no symptoms.
- They are discovered incidentally due to trivial trauma and when undergoing radiograph on nearby joints or bone for other causes.
- Lesions in small bones of hands and feet when present for a long duration or associated with trauma may present with pain and swelling.
- Pathological fracture is rare and they can heal conservatively.
- Increased pain and swelling not correlating with symptoms or size is suspected to have malignant transformation.
- Plain radiographs show a well defined lesion with punctate calcifications (size less than 5 cc, no endosteal scalloping nor any cortical breach or periosteal reaction).
- Aggressive lesions or malignant transformed lesions can present with surrounding bone destruction and alteration in bone architecture.
- MRI shows features of benign cartilage neoplasm, homogenous lesion without enhancement on IV contrast if given.
- FDG PET CT scan is done in rare situations when the suspicion of malignant transformation is high.
What are treatment options for enchondroma?
Natural history of most enchondromas is to remain static, Hence they can be conservatively managed with follow up as necessary.
- Very few enchondromas become active during one’s life, who present with pain or imaging features of active disease.
- If symptomatic(pain or pathological fracture), enchondroma should undergo a Biopsy to confirm the active status(clinical and imaging inputs are crucial).
- If Surgery is required, they can be treated by Extended Curettage with or without Bone Grafts and substitutes.
- Local recurrence after surgical treatment is rare.
Occurrence of local recurrence after treating a primary enchondroma can give rise to suspicion of chondrosarcoma (Grade I or 2).