RESUMO
Waldenström's macroglobulinemia (WM) is one of malignant hematological disease on account of abnormal proliferation of B lymphocyte clone and the pathologic cells of WM possess ability to secrete monoclonal immunoglobulin M. In this study, the diagnosis and morphological characteristics of 2 patients with WM were analyzed. The results showed that a special kind of "foam cells" were found by cytochemical staining examinations in both cases, which displayed characteristics of lymphocytes, but neither monocyte-macrophage nor fatty cells. The periodic acid-Shiff's reaction (PAS) demonstrated strong positive, especially on the inclusion bodies in pathologic cell plasma while the acid phosphatase, and alpha-butanoic acetate esterase stainings, resulted both in negative. In conclusion, the cells found in the two cases reported may be described as gemmy ring-like lymphocyte in morphology, a special subtype of ring-like lymphocyte.