Radiologic bone changes of polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy.

More than 50 cases of polycystic lipomembranous osteodysplasia (PLO) with sclerosing leukoencephalopathy (SL) have been described in Finland, Sweden, Japan, and in the USA. Radiographic bone changes, including symmetrical cystic lesions in the small bones of the extremities and trabecular loss in the distal ends of the long tubular bones, represent primary abnormalities in the diagnosis of the disease. Neuropsychiatric symptoms, frontal syndrome, and pyramidal signs make the patients dangerous to themselves. They are often involved in traffic accidents and are prone to multiple spontaneous or almost spontaneous fractures. PLO usually starts with slight bone pain around the age of 20 years. Progress is very slow during the next ten years, but faster after the age of 40 years. The patients usually die before the age of 50 years having total dementia and epileptiform convulsions.