Orthopaedic Case Studies
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: 
          - 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.









Solitary Epiphyseal Enchondromas.



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

Last updated by Data Trace Staff on Monday, November 14, 2016 5:44 am

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