Histological analysis of the tumor. (a) Amorphous eosinophilic deposits (hematoxylin and eosin staining). (b) Amorphous deposits are strongly PAS positive. (c) Most of the lymphoid cells express CD20. d) Few infiltrating CD3 positive T-cells are observed. Amorphous deposits and plasmacytic cells stain positive for Ig-A heavy chain (e) and for λ-light chain antibody (f).