Two cases of pulmonary Waldenström's macroglobulinemia.

Two cases of Waldenström's macroglobulinemia (WMG) with principally pulmonary manifestation are presented. The disease in both cases was discovered from abnormal shadow in chest x-ray films, without classic features of the disease such as anemia, lymphadenopathy, hepatosplenomegaly or visual disturbance. Transbronchial biopsy (case 1) and open lung biopsy (case 2) revealed diffuse infiltration of lymphoplasmacytoid cells. In both cases, the cytoplasm of proliferating cells stained for monoclonal IgM by the peroxidase-antiperoxidase method. Immunologic examination revealed that almost all tumor cells obtained from bronchoalveolar lavage fluid (case 1) and cell suspension of the right lung (case 2) had monoclonal surface immunoglobulin for IgM. These data established the diagnosis of pulmonary WMG. These cases indicate the importance of immunologic studies for establishing a diagnosis of pulmonary WMG, since histologic findings in biopsy specimens and clinical features are often not specific enough for making this diagnosis.