title: [Hereditary multiple exostoses after 40 years of development: a case report].
abstract: BACKGROUND
  Hereditary multiple exostoses is an autosomal dominant skeletal disorder with genetic heterogeneity and an estimated prevalence of 1/50,000 in western countries. Malignant degeneration is a rare (about 2%) but classical complication in patients with hereditary multiple exostoses. At least 3 loci identified as EXT 1, EXT 2 and EXT 3 are involved in this skeletal disease.
  
  
  METHODS
  The case of a 45-year old man is described with 15 years follow-up after resection of a well-differentiated chondrosarcoma (grade I), which arose from a right posterior pelvic exostosis. The observed radiological lesions remained relatively stable until now. The genetic mutation which is responsible for the disease was determined at the locus EXT 1.
  
  
  CONCLUSIONS
  The present case report illustrates the natural history of hereditary multiple exostoses, especially since the patient underwent a malignant degeneration which could be resected without recurrence. The results of the genetic analysis contributed to the understanding of the pathophysiology of the disease.
authors.affiliation: Service de médecine interne, hôpital Saint-Louis, 1, avenue Claude-Vellefaux, 75475 Paris, France.
authors.forename: J
authors.initials: J
authors.lastname: Rambeloarisoa
authors.forename: M
authors.initials: M
authors.lastname: el Guedj
authors.forename: L
authors.initials: L
authors.lastname: Legeai-Mallet
authors.forename: A M
authors.initials: AM
authors.lastname: Zagdanski
authors.forename: G
authors.initials: G
authors.lastname: Délépine
authors.forename: M
authors.initials: M
authors.lastname: Le Merrer
authors.forename: D
authors.initials: D
authors.lastname: Farge
mesh_terms: D001859:Bone Neoplasms / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D002471:Cell Transformation, Neoplastic; D002813:Chondrosarcoma / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D018450:Disease Progression; D005097:Exostoses, Multiple Hereditary / Q000473:pathology*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis