Diffuse idiopathic skeletal hyperostosis in a patient with idiopathic retroperitoneal fibrosis: a case report.

Idiopathic retroperitoneal fibrosis (IRF) is a rare rheumatologic disease with obscure pathogenesis. Its manifestations depend upon the structures involved. Diffuse idiopathic skeletal hyperostosis (DISH) is usually seen in male patients over 45 years of age and characterized by new bone formation at the entheses. The dorsal spine is most commonly involved, but radiographic findings in both the spine and extraspinal structures suggest a generalized disorder of ossification rather than a localized spinal disease. The association of IRF and DISH has not been reported before. There is proliferation of connective tissue in both of these diseases, and they may share a common etiopathogenetic basis. We describe a patient having features of both IRF and DISH.