Duke Orthopaedics
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Wheeless' Textbook of Orthopaedics

Chondroblastoma


- See: Bone Tumor Menu

- Discussion:
    - age at presentation:
          - most common primary epiphyseal tumor in children is chondroblastoma;
          - most commonly arises between ages 10 to 30;
          - not infrequently, the tumor will also arise in adults;
          - the adults counterpart of chondroblastoma is giant cell tumor;
          - in the report by Ramappa AJ, et al, 62 % of the 47 patients were 20 of age or younger (in contrast, 38% of patients will be
                   well beyond skeletal maturity);
    - location:
          - lesions are distributed widely in the skeleton, but most were in the epiphyses or apophyses;
          - most lesions occur in the proximal part of the tibia (17%) and the proximal part of the humerus (15%); (Ramappa AJ, et al)
          - may occur in the apophysis of the greater trochanter;
          - of note, chondroblastoma is the most common tumor affecting the patella, followed by giant cell tumor;  
          - metastatic lesions are uncommon but due occur;
    - males more affected than females;
    - diff dx:
          - only three tumors may invade physis: chondroblastoma, GCT, and clear cell chondrosarcoma;
          - GCT of bone:
                  - GCT usually arises in the 3-4 decade (where as chondroblastoma arises in the second);
                  - GCT may expand to both the epiphysis and diaphysis;
          - clear cell chondrosarcoma (see chondrosarcoma)
                  - clear cell sarcoma is rare, slow growing, locally recurrent tumor easily confused with chondroblastoma but malignant;
          - epiphyseal osteomyelitis: (see: osteomyelitis);
                  - ref: Primary subacute epiphyseal osteomyelitis.

- Clinical Presentation:
    - painful - motion limiting, benign tumor arising during adolescence;
    - majority are active stage 2 lesions;

- Radiographs:
    - look for epiphseal radiolucent lesion w/ fine punctate calcifications (mineralization and a well-marginated rim of reactive bone);
    - oval osteolysis located eccentrically in the epiphysis;
    - slight bone expansion and broading of cortex;
    - tumor is usually bordered by a well defined margin of reactive bone.
    - note the amount of epiphyseal involvement and whether the tumor crosses the growth plate;
    - stage 3 chondroblastoma may extends thru growth plate into metaphysis or through articular cartilage into the joint;
    - in some cases, the tumor will erode through the subchondral bone; 

- CT Scan:
    - useful in demonstrating tissue density, extent of epiphyseal involvement, and often most imporatant location
             of lesion in relation to the articular and epipyseal cartilage;

- Histology of Chondroblastoma:
    - may contain areas that are histologically identical to aneurysmal bone cyst


- Treatment:
    - because condroblastoma may extend upto subcondral bone, it is difficult to perform marginal excision or complete curettage;
    - in older adolescents, currettage of growth plate may promote ephyseal closure (which avoids angular deformities);
           - references:
                  - What Happens to the Articular Surface After Curettage for Epiphyseal Chondroblastoma?
    - stage 2
           - most chondroblastomas are active stage 2 tumors which are amenable to treatment by curettage w/ moderate risk of recurrance;
           - consists of intralesional curettage and packing with allograft or autograft bone chips or polymethylmethacrylate
           - it is important to avoid joint penetration because chondroblastoma cells will grow in joint fluid;
           - addition of methylmethacrylate to defect may be added to curettage to prevent recurrence;
    - stage 3 chondroblastoma (most common in pelvis) is not amenable to curettage due to 50% recurrance rate;
           - wide excision is the treatment of choice, if technically possible;
           - stage 3 will require en bloc excision;
           - these may metastasize to the lungs;
           - 7 patients (15 %) had a local recurrence; 3 of them had a second recurrence and one, a third recurrence;
           - patients w/ lesions around the hip (proximal femur, greater trochanter, and pelvis) are significantly more likely to develop
                      recurrences as well as metastatic lesions (Ramappa AJ, et al)



Chondroblastoma. A review of seventy cases.

Chondroblastoma.     

Chondroblastoma of Bone.

Chondroblastoma of bone: long-term results and functional outcome after intralesional curettage. 

Treatment and Prognosis of Chondroblastoma.

Chondroblastoma of bone in the extremities: a multicenter retrospective study.



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

Last updated by Data Trace Staff on Monday, August 8, 2016 5:47 am

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