What're the symptoms of fibrous dysplasia?
Fibrous dysplasia is characterized by uneven growth, pain, brittleness, and deformity of the affected bones. This disorder may involve a single bone (monostotic fibrous dysplasia or Jaffe-Lichtenstein disease) or may affect multiple bones (polyostotic fibrous dysplasia). Fibrous dysplasia is usually evident during childhood, and the bone lesions usually stop
developing at puberty. These lesions may be painful, deforming and widespread. Children experience fibrous dysplasia in a wide range of severity. Some experience many symptoms associated with endocrine abnormalities, while others appear entirely healthy, with little or no evidence of bone or endocrine involvement.
Bone pain may occur due to the expanding fibrous tissue in the bone. The onset of pain may signal an impending fracture in a bone that has been weakened by this gradual expansion. A fracture may cause a sudden increase in severe pain. It is also possible, although less common, for abnormal bone to produce pain by pressing on an adjacent nerve. In patients with considerable deformity of the weight-bearing long bones (thighs and shins), arthritis can develop in the hips and knees. Because fibrous dysplasia can affect any bone, bone deformity can occur anywhere in the skeleton. Bone deformity caused by fibrous dysplasia is most obvious when it occurs in the skull and facial bones. Fibrous dysplasia of the skull may cause loss of vision and hearing. When a bone is affected by fibrous dysplasia, the fibrous, or connective, tissue expands while the bone surrounding the fibrous tissue breaks down. Therefore, even though the fibrous tissue thickens, the bone itself becomes thin and fragile and fractures can occur. This occurs most often in the long bones of the legs.
Fibrous dysplasia may be associated with endocrinopathies in 2-3% of cases; these include precocious puberty in girls, hyperthyroidism, hyperparathyroidism, acromegaly, diabetes mellitus, and Cushing syndrome. McCune-Albright syndrome may be associated with hyperthyroidism and, hence, exophthalmos. Sexual precocity in girls, with polyostotic fibrous dysplasia and cutaneous pigmentation, constitutes McCune-Albright syndrome. Cutaneous pigmentation is the most common extraskeletal manifestation in fibrous dysplasia. It occurs in more than 50% of cases of the polyostotic form. Cutaneous pigmentation in polyostotic fibrous dysplasia is ipsilateral to the side of bony lesions, a feature that differentiates this disease from pigmentation in neurofibromatosis. |
