Characteristic radiological feature of fibrous dysplasia
Ans is 'c' i.e. Ground glass appearance "In long bones, the fibrous dysplastic lesions are typically well-defined, radiolucent areas with thin cortices and a ground-glass appearance "- HarrisonFibrous DysplasiaIt is characterized by the replacement of normal lamellar cancellous bone by an abnormal fibrous tissue that contains small, abnormally arranged trabeculae of immature woven bone.It may affect one bone (monostotic form) or several bones (polyostotic form).The monostotic form is the most common and is usually diagnosed in patients between 20 and 30 years of age without associated skin lesions. The polyostotic form typically manifests in children <10 years of age and may progress with age. Monostotic fibrous dysplasia most commonly affects the femur--particularly the femoral neck--as well as the tibia and ribs.Polyostotic fibrous dysplasia most commonly affects the maxilla and other craniofacial bones, ribs, and metaphyseal or diaphyseal portions of the proximal femur or tibia.Radiographic FindingsIn long bones, the fibrous dysplastic lesions are typically well-defined, radiolucent areas with thin cortices and a ground-glass appearance. The articular ends are usually spared.Involvement of facial bones usually presents as radiodense lesions, which may create a leonine appearance (leontiasis osea).TreatmentThere is no established effective treatmentIV bisphosphonate therapy- Improvement in bone pain and partial or complete resolution of radiographic lesions have been reported after IV bisphosphonate therapySurgical stabilization is used to prevent pathologic fracture or destruction of a major joint space and to relieve nerve root or cranial nerve compression or sinus obstructionComplicationsMost common complication is pathologic fractureShepherd's crook deformity - If fracture occurs at the femoral neck, it commonly leads to a deformity called "shepherd's crook"Expanding bone lesions may cause pain, deformity and nerve entrapment.Sarcomatous transformation of either form of fibrous dysplasia is extremely rare, but it may occur spontaneously or, more commonly, after radiation therapyAssociated Disorders Albright-McCune SyndromeIt includes:polyostotic fibrous dysplasiaendocrine hyperfunction (pseudo-precocious puberty)abnormal pigmentationThe most common Endocrinopathy assoc. with Albright McCune syndrome is isosexual pseudo-precocious puberty in girls.Other less common endocrine disorders include thyrotoxicosis, Cushing syndrome, acromegaly, hyperparathyroidism, hyperprolactinemia, and pseudo-precocious puberty in boys.Much more common in girls (Male Female ratio-1:10)* The cafe au lait spots seen in Albright-McCune syndrome have characteristically irregular ragged borders (commonly called "coast of Maine" borders), as opposed to the smoothly marginated borders ("coast of California") of the spots seen in neurofibromatosis.Mazabraud Syndrome It includes:polyostotic fibrous dysplasia andsoft-tissue myxomas
Thickened bone matrix
Cortical erosion
Ground glass appearance
Bone enlargement
Bone Tumour