Nodular pulmonary amyloidosis associated with benign hypergammaglobulinemic purpura.

A 59-year-old woman, who had had benign hypergammaglobulinemic purpura for three years, developed a solitary amyloid nodule of the lung. The benign hypergammaglobulinemia was associated with an IgG band of restricted heterogeneity and IG2-IgG3 subclass containing complexes of intermediate size with rheumatoid factor activity. Serum levels of IgA and IgM were also increased. Autopsy after death from an unrelated cause revealed no amyloid in the remainder of the lungs or other organs and no evidence of lymphoproliferative disorder.