[Fibrous dysplasia and McCune-Albright syndrome: case-report and differential diagnose with Paget bone disease].

Fibrous dysplasia of bone or Jaffe Lischtenstein's disease is a genetic, non-inheritable disease of bone development, characterized by bone pain, deformities and fracture, mainly observed in yo ung adults. The frequency is equal between sexes. Mutations in the gene coding the Gsα, GNAS complex, results in osteoblastic differentiation defects, and bone resorption. The disease can have a monostotic or polyostotic form, or be associated with café-au-lait skin spots and precocious puberty (McCune-Al bright syndrome). The normal bone and bone marrow is replaced with abnormal benign intramedullary fibro-osseous tissue, and can involve any bone in the body. The vertebral involvement is rare. Radiological and pathological findings can be diagnostic. Biphosphonates and calcium, vitamin D and phosphorus supplements have been used in fibrous dysplasia treatment. Osteosarcoma is a rare, but serious malignant complication. We report the case of a 68 year old woman with a history of hypofisectomy, with a progressive low back pain, without systemic or neurological symptoms. The bone scan, the ra di o graphs and the computed tomography findings revealed polyostotic fibrous dysplasia, with vertebral and mandibular involvement. In this paper we compared fibrous dysplasia of bone with Paget bone disease.