- See: Bone Tumor Menu
- Discussion:
- malignant cartilaginous tumor of bone (3rd most common malignant bone tumor / comprises 20% of malignant bone lesions);
- it is less common and less aggressive than osteosarcoma;
- staging:
- histologic grading is best predictor of stage;
- most often presents as a low grade - intracompartmental lesion;
- grade-1: almost never metastasize and are difficult to differentiate from benign enchondroma
- on serial radiographs at monthly intervals grade 1 tumors will continue to grow where as enchondromas never grow;
- they are slow to metastasize and may grow to immense proportions;
- tumor tends to destroy bone and to extend into the soft tissues;
- tumor may invade blood vessels and produce long intravascular tumor bungs that may extend into heart and
pulmonary arteries;
- long-term survival rate of patients w/ treated chondrosarcoma is between 50-75%.
- von Hippel-Lindau tumor suppressor gene (VHL), located in chromosome 3p25 may be involved in chondrosarcoma
formation;
- primary form occurs most often in men between 50-60 yrs of age (where as osteosarcoma occurs between 20-30 yrs of age);
- location:
- pelvis, proximal femur, & shoulder girdle (where as osteosarcoma occurs most often around the knee;
- when chondrosarcoma occurs in the pelvis, it is often large, high grade, diagnosed late, and has a poor prognosis;
- in report by Pring ME, et al. (2001), 64 patients with localized pelvic chondrosarcoma that had been surgically treated between
1975-96 were reviewed;
- there were 41 male and 23 female patients who had a mean age of 47 years;
- 33 of the 64 patients were first seen with grade-1 chondrosarcoma;
- 23, with grade-2; one, with grade-3; and seven, with grade-4 (dedifferentiated chondrosarcoma);
- 13 patients had a hemipelvectomy to get tumor control, whereas 51 patients underwent a limb-salvage procedure;
- 12 (19%) had local recurrence, and eleven (17%) had distant metastases;
- at follow-up, 44 (69%) were alive w/o evidence of dz, 13 (20%) had died of dz, 6 (9%) had died of unrelated causes,
and 1 (2%) was alive w/ dz;
- less than a wide surgical margin correlated with local recurrence (p = 0.014);
- high-grade tumors correlated with poor overall survival (p < 0.001);
- all patients who had a limb-salvage procedure were able to walk at the time of the final follow-up;
- ref: Chondrosarcoma of the Pelvis. A Review of Sixty-four Cases.
- secondary chondrosarcoma:
- occurs in about 25% of cases;
- it is a malignant transformation from preexisting enchondroma or osteochondroma;
- Variants of Chondrosarcoma: (based on histology & location);
- dedifferentiated (high grade)
- rare type of high grade chondrosarcoma which arises from a low grade chondrosarcoma;
- a high-grade spindle-cell sarcoma coexists with a lower-grade chondroid tumour;
- histologically there will be areas c/w MFH, osteosarcoma, or fibrosarcoma;
- high risk for metatastasis, only 5% of patients will survive more than 5 years;
- references:
- Dedifferentiated chondrosarcoma
- Dedifferentiated chondrosarcoma. A report of the clinicopathological features and treatment of seventy-eight cases.
- Experience in the treatment of dedifferentiated chondrosarcoma.
- extraosseous chondrosarcoma:
- Extra-osseous chondrosarcoma. Report of five cases and review of the literature.
- clear cell (intermediate grade)
- rare, slow growing, locally recurrent tumor easily confused w/ chondroblastoma but malignant;
- tumor is especially rare in a child or adolescent;
- may invade epiphysis;
- most common in proximal femur (over 50%) followed by proximal humerus;
- microscopically, sheets of cartilaginous cells in a lobular arrangement are mixed with scattered giant cells;
- this radiolucent lesion is often misdiagnosed and undertreated;
- references:
- Chondrosarcoma: clear-cell variant. A report of sixteen cases.
- Year Book: Clear Cell Chondrosarcoma of Bone: Observations in 47 Cases.
- Radiologic case study. Clear cell chondrosarcoma.
- Clear cell chondrosarcoma.
- Clear cell chondrosarcoma of bone: long time follow-up of 18 cases
- Year Book: Clear-Cell Chondrosarcoma: A Report of Ten Cases and Review of the Literature.
- atypical enchondroma (juxtacortical chondroma)
- histologic exam of a low grade chondrosarcoma may show nodular cartilage tissue with mostly isomorphic tumor cells;
- tissue samples show cellularity than is seen w/ enchondroma;
- differentiating between this malignant tumor growth and an enchondroma can be extremely difficult;
- an aysmptomatic - well circumscribed calcified lesion which has not changed in size is most consistent w/ an enchondroma;
- more peripherally located lesions are also more likely to represent an enchondroma;
- references:
- Low risk of recurrence of enchondroma and low grade chondrosarcoma in extremities. 80 patients followed for 2-25 years.
- Clinical Findings:
- persistent, dull, aching pain;
- found in an older age group, peaking at age 45 years;
- majority of chondrosarcomas occur about the hip and pelvis.
- Histology: 
- grade 1:
- may be identical to benign enchondroma;
- where as a low grade malignant appearing cartilagenous tumor of extremities may actually be an enchondroma, a centrally
occurring malignant appearing enchondroma in an adult is more likely represents a chondrosarcoma;
- grade 2:- increased cellularity but rarely have mitotic figures and are more locally aggressive, with a 15% to 20% rate of metastasis;
- grade 3: (dedifferentiated and mesenchymal types) mitotic figures with increased cellularity, leading to a 70% rate of metastasis;
- Radiographic Studies:
- subtle, radiolucent, permeative lesion;
- lytic lesions that often erode the cortex with or without cortical thickening
- may have hazy or speckled calcifications w/ either a diffuse "salt & pepper" pattern or a more discrete "pop corn" pattern;
- pattern of calcification is usually diagnostic of cartilaginous tumor;
- Treatment:
- tumor does not respond to x-ray therapy nor to currently available antineoplastic drugs;
- low grade tumors:
- rarely metastasize;
- rarely recurs after wide limb salvaging excision;
- the involved bone is resected along w/ a small cuff of surrounding muscle;
- ref: How safe is curettage of low-grade cartilaginous neoplasms diagnosed by imaging with or without pre-op needle biopsy?
- high grade tumors
- have higher rate of recurrence after limb salvage (requires amputation)
- are prone to pulmonary metastases.
A New Histologic Approach to the Differentiation of Enchondroma and Chondrosarcoma of the Bones: A Clinicopathologic Analysis of 51 Cases.
Amputations and Artificial Limbs--General Orthopaedics: Tumors: Periosteal Chondroma: A Report of Ten Cases and Review of the Literature.
S-100 protein in human cartilage lesions.
Chondrosarcoma in Maffucci's syndrome.
The biology of human chondrosarcoma. I. Description of the cases, grading, and biochemical analyses.
Extra-articular synovial chondromatosis.
Chondrosarcoma of the Hand: is a Wide Surgical Resection Necessary?
Recent advances in the basic science of chondrosarcoma.
Surgical treatment and outcome of conventional pelvic chondrosarcoma.