Monoclonality of infiltrating plasma cells in primary pulmonary nodular amyloidosis: Detection with polymerase chain reaction

Abstract

Aims - To investigate the relation between localised amyloidosis and immunocytic dyscrasia. Methods - Open lung biopsy specimens from a 72 year old man with multiple nodules in the right middle and lower lung. were stained with haematoxylin-eosin, Congo red, and antibodies against IgG, IgA, IgM, and κ and λ light chains. Semi-nested PCR amplification for the immunoglobulin heavy chain (IgH) gene was performed using consensus primers for the VDJ region of the IgH gene, FR3A, LJH, and VLJH. Results - The biopsy specimens contained eosinophilic amorphous material stained with Congo red and anti-κ light chain, and surrounded by inflammatory cells intermingled with plasma cells. Plasma cells in the adjacent amorphous material showed cytoplasmic staining with anti-κ. Polymerase chain reaction revealed a discrete amplified band of apparently uniform size with background smear. Conclusions - Primary AL type localised amyloidosis involves local accumulation of monoclonal plasma cells and their secreted products, as in nodular cutaneous amyloidosis. Localised AL type nodular amyloidosis is a separate entity in amyloidosis.