Amyloid in intervertebral discs. A histopathological investigation of intervertebral discs from 30 randomly selected autopsies.

Material from intervertebral discs obtained from 30 randomly selected autopsies was examined histologically for amyloid deposits. Various degrees of amyloid degeneration were found in the disc tissue from 28 of the autopsies. In the annulus fibrosus, the amyloid was lying between the thick bundles of collagen fibers, compared to a more diffuse nodular distribution in the nucleus pulposus, frequently in close relation to chondrocytes. With regard to the lumbar discs, a significant correlation was found between the occurrence of islands of chondroid tissue in the annulus fibrosus and amyloid degeneration. Significantly more amyloid was observed in disc tissue in older age groups, while the amount of amyloid was similar in discs from men and women. Calcium-pyrophosphate-dihydrate (pyrophosphate) was found in the tissue of 6 of the 7 women over the age of 70. Calcium phosphate was seen in 22 of the autopsies--more frequently in the annulus fibrosus than in the nucleus pulposus. There was no topographical relationship between calcium phosphate and amyloid.