Radiographic and pathologic features of spinal involvement in diffuse idiopathic skeletal hyperostosis (DISH).

The vertebral involvement of DISH is described from an evaluation of 215 cadaveric spines and 100 patients with the disease. Radiographic features include linear new bone formation along the anterolateral aspect of the thoracic spine, a bumpy contour, subjacent radiolucency, and irregular and pointed bony excrescences at the superior and inferior vertebral margins in the cervical and lumbar regions. Pathologic features include focal and diffuse calcification and ossification in the anterior longitudinal ligament, paraspinal connective tissue, and annulus fibrosis, degeneration in the peripheral annulus fibrosis fibers, L-T-, and Y-shaped anterolateral extensions of fibrous tissue, hypervascularity, chronic inflammatory cellular infiltration, and periosteal new bone formation on the anterior surface of the vertebral bodies.