Tomographic and Histological Analyses of Ectopic Calcification Associated With Diffuse Idiopathic Skeletal Hyperostosis (DISH)

Diffuse idiopathic skeletal hyperostosis (DISH) is a non-inflammatory spondyloarthropathy characterised by the formation of ectopic calcifications of the ligaments/enthuses along the anterolateral aspect of the vertebral column. Despite affecting 15-25% of North Americans over the age of 50, the aetiology of DISH is poorly understood and there are no disease modifying treatments. Our discovery-based approach implemented a transdisciplinary research team to study the basic biology, imaging science, clinical anatomy and significance of DISH in humans. Our novel characterisation defined distinct morphological presentations of ectopic calcifications associated with DISH in cadaveric specimens using micro-computed tomography imaging. Subsequent histopathological analyses demonstrated that flowing bridges characteristic of DISH are composed of both ectopic ossifications and discrete regions of amorphous calcifications within fibrocartilage structures. These findings provide newfound insight into the pathogenesis of DISH and that the current diagnostic criteria captures a heterogenous population of presentations, or distinct pathologies that must be further defined