Lymphosarcoma cell leukemia and other non-Hodgkin's lymphomas in leukemic phase.

Lymphosarcoma cell leukemia has been used to refer to three related clinical syndromes. As originally described, it refers to the invasion of peripheral blood by poorly-differentiated lymphocytic lymphoma. Blood involvement occurs in 10 to 70 percent of patients with poorly-differentiated lymphocytic lymphoma, depending on the methods and criteria used to define leukemic phase, but it may have little impact on the clinical course of such patients. Second, lymphosarcoma cell leukemia can describe a variant of chronic lymphocytic leukemia, presenting clinically without lymphoma. Although not all hematologists recognize this as a distinct entity, others believe that such patients have a poorer prognosis than those with typical chronic lymphocytic leukemia. In the absence of a lymph node biopsy diagnostic of poorly-differentiated lymphocytic lymphoma, the diagnosis of lymphosarcoma cell leukemia should be reserved for cases demonstrating immunologic features of poorly-differentiated lymphocytic lymphoma, namely bright surface immunoglobulin immunofluorescence, normal capping, and low mouse red cell rosette formation. Finally, lymphosarcoma cell leukemia has been used to describe the invasion of blood by other types of lymphoma, including large cell, lymphoblastic, and Burkitt's lymphoma, although these are better designated as the particular lymphoma in leukemic phase. When abnormal cells appear in the blood samples of patients with lymphoma, acute myelogenous leukemia must also always be considered, particularly in patients who have received substantial prior chemotherapy or irradiation.