Primary localized amyloidosis of the bladder with a monoclonal plasma cell infiltrate.

A case of primary tumour-like amyloidosis of the urinary bladder is described. The plasma cell infiltrate around the amyloid deposition revealed monoclonality by both immunoperoxidase and immunofluorescence methods and the amyloid gave a staining reaction consistent with AL type. A local tissue based immunocyte dyscrasia appears to be responsible for the tumour-like amyloid deposition.