Musculoskeletal symptoms as a presenting sign of long-standing hypothyroidism.

: Muscle and joint pains and/or weakness are not usually stressed as central symptoms in hypothyroidism. Two cases of long-standing hypothyroidism presenting with prominent myopathic symptoms are described. The first patient presented with a 12-year history of proximal myopathy, arthropathy and skin abnormalities, and florid primary myxedema was diagnosed. No evidence for a systemic autoimmune process was found. The second patient had been treated with irradiation to the neck 23 years before admission and presented with clinical and laboratory signs of both proximal myopathy and hypothyroidism. Thyroid hormone replacement resulted in a complete recovery of all the musculoskeletal symptoms, with reversion to normal of the very high muscle enzyme levels in both patients. The cases presented illustrate that hypothyroidism can lead to the development of a variety of muscular, rheumatic and dermatologic syndromes easily confused with dermatomyositis or other collagen diseases.