[A very unusual case of amyloidosis].

This case report describes a patient with IgG lambda myeloma and vascular amyloidosis. Remarkable is the presence of mesangial granular deposits revealed by electron microscopy and positive with anti-IgG and anti-kappa anti-serum in an immunofluorescence study. Granular dense deposits were also found at the inner side of the basement membrane of the skin and were positive with anti-kappa anti-serum in immunofluorescence study. Because no L kappa q light chain proliferation could be demonstrated, the nature and significance of these kappa deposits are not clear.