AMYLOID DEPOSITS OF THE PITUITARY IN OLD-AGE - CORRELATION WITH HISTOPATHOLOGICAL ALTERATIONS

The prevalence and quantification of amyloid formation and the frequen cy of histomorphological alterations affecting the pituitary gland wer e studied in a consecutive autopsy series performed on 109 patients ol der than 84 years of age; 87 (80%) pituitaries had amyloid in the ante rior lobe. A polyclonal antibody directed against amyloid of h-light c hain origin immunostained pituitary amyloid in every specimen, whereas all other antisera directed against the precursor proteins of the rem aining major amyloid syndromes and pituitary hormones did not. Because no case studied suffered from a generalized h-light chain amyloidosis , immunostaining might be due to crossreaction with a hitherto unident ified precursor protein. Histomorphological alterations were observed in many pituitaries, and they were differentiated into regressive chan ges, cysts of the intermediate zone, so called basophilic invasion of the posterior lobe, hyperplasia, Erdheim's squamous epithelia, and ade nomas. Statistical analysis failed to reveal any correlations between the presence of histopathological alterations and the frequency or the amount of interstitial amyloid. Nonetheless, we were not able to expl ain amyloid formation in old age, especially none that was due to hist omorphological alterations of the pituitary gland. Thus, other disease s that primarily do not affect the pituitary may actually influence pi tuitary amyloid formation.