title: Malignant change secondary to fibrous dysplasia.
abstract: BACKGROUND
  Malignant change in fibrous dysplasia (FD) is very rare. This study was carried out to establish some characteristic clinical information about this disorder.
  
  
  METHODS
  Four cases with a malignant change in FD out of 128 cases with FD were surgically treated and followed up for a median period of 61.3 months. The mean age of the patients was 39.8 years. Clinical features, radiological findings, and the outcome were analyzed for each of the four cases.
  
  
  CONCLUSIONS
  The sites of the lesions were tibia (2 cases), femur (1 case), and rib (1 case). The forms of FD were monostotic in one case and polyostotic in three cases. Radiologically, plain films and computed tomography (CT) showed osteolytic lesions with poorly delineated margins within and/or near areas having a ground-glass appearance. In the osteolytic lesions, simple cystic changes associated with old FD could be excluded by enhanced magnetic resonance imaging (MRI). Histopathologically, two cases were osteosarcoma, one case was malignant fibrous histiocytoma (MFH), and one case was fibrosarcoma. The management of this disease should be decided according to the type of primary high-grade bone sarcoma. One patient, with MFH, was dead of lung metastasis 13 months after surgery. The others are alive without disease.
authors.affiliation: Department of Orthopaedic Oncology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan, smatsumoto@jfcr.or.jp.
authors.forename: Manabu
authors.initials: M
authors.lastname: Hoshi
authors.forename: Seiichi
authors.initials: S
authors.lastname: Matsumoto
authors.forename: Jun
authors.initials: J
authors.lastname: Manabe
authors.forename: Taisuke
authors.initials: T
authors.lastname: Tanizawa
authors.forename: Toshio
authors.initials: T
authors.lastname: Shigemitsu
authors.forename: Naohiro
authors.initials: N
authors.lastname: Izawa
authors.forename: Kengo
authors.initials: K
authors.lastname: Takeuchi
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Kawaguchi
mesh_terms: D000328:Adult; D001859:Bone Neoplasms / Q000209:etiology* / Q000473:pathology* / Q000628:therapy; D005260:Female; D005266:Femoral Neoplasms / Q000209:etiology / Q000473:pathology / Q000628:therapy; D005357:Fibrous Dysplasia of Bone / Q000150:complications*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012272:Ribs; D012509:Sarcoma / Q000209:etiology* / Q000473:pathology* / Q000628:therapy; D013977:Tibia; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome