Apoptotic amyloid: a study on prostatic amyloidosis with particular reference to corpora amylacea.

1 case of systemic immunocytic amyloid and 20 cases of apoptotic amyloid of the prostate are reported. The latter cases derive from apoptotic (dying) prostatic columnar cells with major protein fibrils identifiable with intermediate prekeratin filaments. The prostatic apoptotic amyloid is tryptophan-positive, permanganate-labile and pronase-resistant. The mean thickness of fibrils is 130 A.