Lymph node involvement in Waldenström's macroglobulinemia.

The pattern of lymph node involvement in Waldenström's macröglobulinemia (MG) is described according to clinical and histological materials from 2 biopsy and 4 autopsy cases. The histological features of biopsy were well-differentiated, diffuse, lymphocytic lymphoma in one case (case 1) and sinus histiocytosis (SH) with nodular aggregates of lymphoid cells as observed by the first biopsy in the other case (case 2). An immunofluorescent study of lymph nodes revealed monoclonal proliferation of B lymphocytes (IgM, gamma) in both cases. In case 2, a majority of circulating lymphoid cells bore membrane-bound monoclonal IgM. The histological features of lymph nodes obtained by the second biopsy in case 2 was comparable with the well-differentiated, lymphocytic lymphoma in some nodes, and diffuse and nodular proliferation with preservation of sinuses in the other nodes. The pattern of lymph node involvement of 4 autopsy cases were also analysed. According to these investigations. It is suggested that lymph node showing SH is a pattern of lymph node involvement of MG.