[Angiofollicular lymphatic hyperplasia with plasmacytoma and polyneuropathy: a case report with immunohistochemical study].

A rare case of a 43-year-old man with polyneuropathy, monoclonal gammopathy, myeloma and Castleman's disease of plasma cell type was diagnosed. Immunohistological examination of the lymph node with Castleman's disease showed polyclonal binding while the myeloma was monoclonal containing IgA with lambda-light chains. At the immunoelectrophoresis IgA/IgA paraprotein was demonstrated. The possible pathogenetical relationship between polyneuropathy and plasmacytoma as well as Castleman's disease will be discussed.