Intermediate grade osteosarcoma and chondrosarcoma arising in an osteochondroma. A case report of a patient with hereditary multiple exostoses
- 1Department of Pathology, Leiden University Medical Center, PO Box 9600, L1-Q, 2300 RC Leiden, The Netherlands
- 2Department of Orthopaedic Surgery, Leiden University Medical Center
- 3Department of Radiology and Nuclear Medicine, Leiden University Medical Center
- Correspondence to: Dr P C W Hogendoorn, Department of Pathology, Leiden University Medical Center, PO Box 9600, L1-Q, 2300 RC Leiden, The Netherlands; P.C.W.Hogendoorn{at}lumc.nl
- Accepted 8 August 2001
Abstract
A 40 year old man with hereditary multiple exostoses (HME), affecting predominantly his left proximal tibia, distal femur, and proximal femur, underwent resection of an osteochondroma near the trochanter major of his left proximal femur because of malignant transformation of the cartilaginous cap towards secondary peripheral chondrosarcoma. The patient had a history of a papillary thyroid carcinoma four years previously. At examination of the resected specimen, a third malignant tumour, an intermediate grade osteosarcoma (grade II/IV), was found in the osseous stalk of the osteochondroma. Although no mutations were found in the EXT1 and EXT2 genes, the genes involved in HME, or in exons 5–8 of the p53 gene, the development of three malignancies before the age of 40 suggests that this patient is genetically prone to malignant transformation.
- HME, hereditary multiple exostoses
- MR, magnetic resonance
- PCR, polymerase chain reaction
- SSCP, single strand conformational polymorphism
