Solid Tumour Section

It is characterized by a broad clinical spectrum, varying from the more frequent solitary (monostatic) asymptomatic lesion to extensive and severe multifocal (polyostatic) lesions. The monostotic variant most commonly affects the ribs, femur and tibia of older children and young adults. The less frequent polyostotic type may be associated with endocrine abnormalities, skin hyperpigmentation and soft tissue myxoma (so-called Albright syndrome). On radiographs, fibrous dysplasia presents as a well defined osteolytic lesion with benign features, centered within the medulla, and frequently bordered by a shell of reactive sclerosis. Depending on the relative proportion of osseous to fibrous tissue, the lesion can be completely lytic or, most typically, show a relatively high density, the so-called Œground-glass' appearance in a least part of it. Especially in bones with small diameter and flat bones, fibrous dysplasia frequently expands the bone.