The Ugly Duchess - portrait by Quentin Matsys. Michael Baum, emeritus professor of surgery at University College London, suggested that the sitter had<unk> . Mild or early cases of<unk> 's are asymptomatic, and so most people are diagnosed with<unk> 's<unk>  incidentally during medical evaluation for another problem. Approximately 35% of patients with<unk> 's have symptoms related to the<unk>  when they are first diagnosed. Overall, the most common symptom is bone pain. When symptoms do occur, they may be confused with those of arthritis or other disorders, and so diagnosis may be delayed.<unk> 's may first be noticed as an increasing deformity of a person's bones.<unk> 's<unk>  affecting the skull may cause frontal bossing, increased hat size, and headaches. Often patients may develop loss of hearing in one or both ears due to auditory foramen narrowing and resultant compression of the nerves in the inner ear. Rarely, skull involvement may lead to compression of the nerves that supply the eye, leading to vision loss. Associated conditions<unk> 's<unk>  is a frequent component of multisystem proteinopathy. Advanced<unk> 's<unk>  may lead to other medical conditions, including: * Osteoarthritis may result from changes in bone shape that alter normal skeletal mechanics. For example, bowing of a femur affected by<unk> 's may distort overall leg alignment, subjecting the knee to abnormal mechanical forces and accelerating degenerative wear. * Heart failure is a rare, reported consequence of severe<unk> 's<unk>  (i.e. more than 40% skeletal involvement). The abnormal bone formation is associated with recruitment of abnormal blood vessels, forcing the cardiovascular system to work harder (pump more blood) to ensure adequate circulation. * Kidney stones are somewhat more common in patients with<unk> 's<unk> . * Nervous system problems may occur in<unk> 's<unk> , resulting from increased pressure on the brain, spinal cord, or nerves, and reduced blood flow to the brain and spinal cord. * When<unk> 's<unk>  affects the facial bones, the teeth may become loose. Disturbance in chewing may occur. Chronic dental problems may lead to infection of the jaw bone. * Angioid streaks may develop, possibly as a result of calcification of collagen or other pathological deposition.<unk> 's<unk>  is not associated with osteoporosis. Although<unk> 's<unk>  and osteoporosis can occur in the same patient, they are different disorders. Despite their marked differences, several treatments for<unk> 's<unk>  are also used to treat osteoporosis.
Paget's disease of bone
Diffuse idiopathic skeletal hyperostosis
Albright's hereditary osteodystrophy
Giant-cell tumor of bone
Fibrous dysplasia of bone
Tumoral calcinosis
Metabolic bone disease
Oncogenic osteomalacia