Seminal vesicle amyloidosis: morphological, histochemical and immunohistochemical observations.

Subepithelial deposits of amyloid were detected within the seminal vesicles of 13 males from a total of 143 unselected autopsies (9%). The incidence increased with increasing age. The amyloid was classified using histochemistry, immunohistochemistry and clinical features. Eight cases were categorized as senile vesicle amyloid, two as systemic AA amyloid with secondary involvement of the seminal vesicle, and three as mixed amyloidosis. The morphological appearances of the different categories of seminal vesicle amyloidosis are similar but a different distribution is common. The staining characteristics of senile vesicle amyloid suggest that this is a different amyloid protein, perhaps locally derived within the seminal vesicle.