Abstract
An osteochondroma is a benign tumour and multiple hereditary osteochondromatosis [MHO] is an auto-somal dominant skeletal disorder in which there are numerous cartilage-capped excrescences. The true incidence of malignant change of osteochondromas is not known, as many osteochondromas, especially solitary lesions, are asymptomatic and usually not reported.
Between the years 1995 to 2002, 11 patients with a secondary chondrosarcoma developing in osteochon-droma were found, out of 300 cases of musculoskeletal tumours treated at our institution. All the patients were treated surgically, The mean follow up of the patients was approximately 2 years [range from 3 months to 4 years]
In radiographs, evidence of malignant change was seen in all the cases. In the cases where MRI was carried out [6 out of 11 cases], the average cartilage cap thickness was 5.0 cm [ranging from 2 to 12 cm].
It is important to recognize the features suggesting malignant change, namely pain, continued growth of the lesion after skeletal maturity, thick bulky cartilaginous cap, and soft tissue mass with or without calcifications. Six of our cases had Grade I chondrosarcoma. High-grade chondrosarcomas occur with greater frequency in patients of multiple hereditary osteochondromatosis. Grading of chondrosarcoma is considered to have prognostic significance. However, the rate of local recurrence is primarily dependent on the adequacy of the primary surgical therapy, rather than the histological grade. In our series we had 3 cases wih local recurrence. In 2 of these cases, intralesional debulking had been done and in 1 case of marginal excision was done. Therefore primary resection [with a cuff of normal tissue] or radical excision appears to be the treatment of choice for these lesions.
The abstracts were prepared by Mr Tim Briggs. (Editoral Secretary 2003/4) Correspondence should be addressed to him at Lane Farm, Chapel Lane, Totternhoe, Dunstable, Bedfordshire LU6 2BZ, United Kingdom
