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Duke Orthopaedics
presents
Wheeless' Textbook of Orthopaedics

Enchondroma


- 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: 
          - 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;
          - may also affect proximal humerus and femoral shaft;
    - risk of transformation:
          - enchondroma 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%;


- 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.



The malignant potential of enchondromatosis

Low risk of recurrence of enchondroma and low grade chondrosarcoma in extremities: 80 patients followed for 2-25 years.  

Enchondromas of the hand: Treatment with curettage and cemented internal fixation

Simple curettage without bone grafting for enchondromata of the hand: with special reference to replacement of the cortical window.

Solitary Epiphyseal Enchondromas.

An Alternative Technique for the Management of Phalangeal Enchondromas With Pathologic Fractures



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Monday, December 31, 2012 11:15 am