[Sarcomatous and leukemic forms of Waldenström's macroglobulinemia].

Four cases of sarcomatous or leukaemic types of Waldenström's macroglobulinemia are presented. They are characterized by tumoral and compressive localizations of lymph node or spleen, or by a hyper-leukocytosis with many circulating abnormal cells. These cells are different from the lympho-plasma cells regularly observed in Waldenström's macroglobulinemia, and can be assimilated to malignant immunoblasts. They have a proliferative aspect and seem to produce less macroglobulin and to recover some beta-glucuronidase activity. The sarcomatous and leukemic types of Waldenström's macroglobullinemia have a poor prognosis and may appear as terminal transformation of the disease.