- See: Bone Tumor Menu / Multiple Enchodromatosis (Ollier's Disease)
- Discussion:
- benign and asymptomatic cartilaginous tumor of bone which most often occurs in adolescents or young adults;
- it is an intramedullary cartilage lesion located in central metaphysis;
- intramedullary tumor develops in adjacent metaphysis and may eventually penetrates the diaphysis;
- results from failure of normal endochondral ossification below growth plate & represents a dysplasia of the central growth plate;
- if dysplastic process occurs in lateral growth plate, resulting tumor is called osteochondroma;
- dysplastic cartilaginous proliferation beneath the perichondrium results in periosteal chondroma;
- sites of involvement:
- may also affect proximal humerus and femoral shaft;
- hand:
- enchondromas are the most common benign skeletal lesions identified in the bones of the hand
- most often affects small tubular bones of hands or feet (40-65%);
- it is a frequent cause of pathologic fracture;
- most frequently involves the proximal phalanx, followed by the middle phalanx, and the metacarpals;
- histologic appearance of an enchondroma in the hand is more cellular than enchondromas found in the long bones;
- references:
- An Alternative Technique for the Management of Phalangeal Enchondromas With Pathologic Fractures
- Enchondromas of the hand: Treatment with curettage and cemented internal fixation
- Simple curettage w/o bone grafting for enchondromata of hand: with special reference to replacement of cortical window.
- risk of transformation:
- usually becomes latent in adulthood, & < 2% of asymptomatic solitary enchondromas will transform to chondrosarcoma;
- enchondromas of long bones have higher chance for malignant transformation;
- in enchondromatosis, risk of malignant transformation is about 10-25%;
- in Maffucci disease (multiple enchondromas and hemangiomas) risk is near 100%;
- references:
- Surveillance of intramedullary cartilage tumours in long bones
- The malignant potential of enchondromatosis
- Low risk of recurrence of enchondroma and low grade chondrosarcoma in extremities: 80 patients followed for 2-25 years.
- Exam:
- enchondroma does not cause symptoms unless there is pathologic frx;
- Histology:
- lobules of different sizes separated by small septa of fibrous tissue;
- may see uniform cartilage cells with dark round nuclei & some binucleate nuclei (which is normal);
- often it is difficult to differentiate an enchondroma from a low grade chondrosarcoma;
- Radiographs:
- central radiolucent lesion w/ well defined miminally thickened bony margin;
- during active phase in adolesence, the lesion may slowly enlarge.
- in children, cortex is usually thin and the lesion is radiolucent;
- later, intralesional calcifications appear;
- there is no periosteal reaction;
- in latent phase, cartilaginous tissue may calcify w/ diffuse punctate pattern;
- as lesion matures, it develops a reactive margin;
- Bone Scans:
- demonstrate radioisotope uptake in margin, related to activity of lesion;
- while there is moderate uptake in the acitive phase there will also be some activity in latent phase;
- Treatment:
- asymptomatic solitary enchondromas may be followed non operatively w/ serial radiographs;
- prognosis for benign enchondroma is excellent.
- if solitary or multiple enchondromas become symptomatic or begin to enlarge, they may require biopsy to r/o malignancy;
- note the terrible triad: pain, increase radioisotope uptake on bone scan, & destructive changes on x-ray;
- pathologic hand and finger fracture:
- in most cases the fracture is allowed to heal with closed treatment;
- curettage and bone grafting is then required after fracture healing;
- spontaneous resolution of the enchondroma following fracture healing is not expected to occur;
- ref: Treatment of solitary enchondromas in fingers.
- excision:
- tumor is excised with a wide margin to reduce recurrance.