Idiopathic hypoparathyroidism mimicking diffuse idiopathic skeletal hyperostosis.

Idiopathic hypoparathyroidism is an uncommon disease caused by insufficient secretion of parathyroid hormone. Idiopathic hypoparathyroidism may cause various musculoskeletal findings, including diffuse ligamentous and entheseal ossifications. Diffuse idiopathic skeletal hyperostosis is a disorder of the elderly characterized by ossification of the anterior longitudinal ligament of the spine and various extraspinal ligaments. We present a 50-year-old man with idiopathic hypoparathyroidism who had been diagnosed as having DISH at 40 years of age. Resistant neck, left shoulder, and left hip pain did not improve with calcium and calcitriol treatment after diagnosis of idiopathic hypoparathyroidism.