A MISLEADING OSTEOLYTIC IMAGE OF THE CLAVICLE

Background: Fibrous dysplasia of bone is a rare congenital disease . Although the radiological findings are diverse and characteristic, atypical and misleading lesions can exist.Objectives: We report the case of a 40 years old woman who was referred to our institution for the diagnosis of a spontaneous fracture of the left clavicleMethods: This patient had a history of recurrent cervical pain since February 2003 with a recent exacerbation. Radiographs showed a heterogeneous lesion wih lytic appearance and cortical bone destruction in the first left rib and in the left clavicle. The bone scan revealed increased uptake in this two regions without any other location. A malignant bone lesion has been suspected but the imaging assessment has not discovered any malignant visceral lesion.Results: The bone scan showed cortical bone destruction of the left clavicle and the left first rib with heterogeneous appearance. The MRI revealed altered signals in the two regions without extension of the lesions in the adjacent soft tissues. Laboratory tests showed increased levels of bone turnover markers. A surgical biopsy established the diagnosis of fibrous dysplasia.Conclusion: Discussion: Fibrous dysplasia can be asymptomatic for a long time particulary in the monosotic forms or can be revealed by deformities, bone pain, fractures or nerve compression. On radiographs, the typical lesions appear with clear borders and the surrounding cortical bone may be respected or eroded. In such cases, it is generally impossible to confirm the diagnosis only by imaging and a bone biopsy is required. Key words: fibrous dysplasia - osteolysis- bone biopsy- bisphosphonatReferences: 1. Lichtenstein L, Jaffe HL, fibrous dysplasia of bone. A condition affecting one, several or many bones, the graver cases of which may present abnormal pigmentation of skin, premature sexual development, hyperthyroidism or still other extra skeletal abnormalities. Arch pathol 1938; 33: 777- 816.2. Avimadje M.A, Goupille P, Zerkak D, Begnard G, Besse J.B, Valat J. Atteinte rachidienne isolée au cours d'' une dysplasie fibreuse. Rev Rhum 2000; 67 (1): 77-82.3. Chapurlat RD. Dysplasie fibreuse des os: aspects cliniques chez l''adulte. Rev Rhum 2003; 70: 678-680.4. Laredo JD, Champsaur P, Hamze B. Dysplasie fibreuse des os et dysplasie ostéofibreuse. Mise au point. Ann Radiol 1995; 38: 225-36.5. Marie P. Dysplasie fibreuse: aspects tissulaires, cellulaires et moléculaires. Rev Rhum 2003; 70: 681-686.6. Henry A. Monostotic fibrous dysplasia. J Bone joint Surg 1969; 51B: 300-6.7. Chapurlat RD, Meunier PJ. Fibrous dysplasia of bone. Baillière''s Clinical Rheumatology 2000; 14 (2): 385- 398.8 Yao L, Eckardt JJ, Seeger LL. Fibrous dysplasia associated with cortical bony destruction: CT and MR findings. J Comput Assist Tomogr. 1994 Jan-Feb; 18(1):91-4.9. Jee WH, Choi KH, Choe By, Park JM, Shin KS. Fibrous dysplasia: MR imaging characteristics with radiologic correlation. AJR 1996; 167: 1523- 27.10. Schwartz DT, Alpert M. The malignant transformation of fibrous dysplasia. Am J Med Sci 1964; 247: 1- 20.11. Ruggieri P, Sim FH, Bond JR, Unni KK. Malignancies in fibrous dysplasia. Cancer 1994; 73: 1411- 24.Citation: Ann Rheum Dis, volume 64, supplement III, year 2005, page 529Session: Bone disease other than osteoporosis