Corpora amylacea in the lung, prostate and uterus. A comparative and immunohistochemical study.

Previous studies have shown that corpora amylacea (CA) in certain organs, including the prostate, lung and uterus, are composed of amyloid. This observation raises the question of whether these amyloid deposits share a common origin or demonstrate the diversity which characterizes other amyloid syndromes. Sections of the lung, prostate and uterus from 110 consecutive autopsies of individuals over 84 years of age were studied initially using H & E and Congo red staining. CA were present in 54 cases (49%) with the prostate affected in 23 cases, the lung in 19 cases and the uterus in 15 cases. Immunohistochemistry with a panel of antibodies directed against the major amyloid fibril proteins, i.e. AA, A beta 2M, A lambda, A kappa and ATTR, yielded strong immunoreactivity of prostatic and pulmonary CA with anti-A beta 2M. Immunostaining with an antibody against cytokeratin (KL1) gave a weak reaction in a single case of prostatic CA, indicating that it is unlikely that these CA derive from cytoskeletal remnants of shedded epithelial cells. The uterine CA were not stained by any of the antibodies, suggesting that they have a different origin than prostatic and pulmonary CA. The influence of the local calcium concentration and niduses on the pathogenesis of CA is discussed.