Burkitt's leukemia: a re-evaluation

Flow cytometric analysis of cytokinetics of L3-acute lymphoblastic leukemia/lymphoma

Cell kinetic differences have been described between acute lymphoblastic leukemia with L1 and L2 morphology. We now report cytokinetic and DNA ploidy findings of the rare L3 B-cell leukemia/lymphoma. Flow cytometry analysis of nineteen samples was performed by simultaneous DNA-RNA staining with acridine orange. RNA and DNA indices and cell cycle distributions were calculated. The RNA-index of the G0/G1 cells was 17.9 +/- 8.7 and the number of cells in S phase and S + G2M were 21 +/- 10.6 and 28.0 +/- 13.9 percent respectively. DNA aneuploidy was found in 6/19 (31.6%) and in two cases multiple aneuploid cell lines were observed. DNA aneuploidy and multiple abnormal stemlines adversely affected survival (p less than 0.05), while kinetic parameters did not affect survival (p greater than 0.05). The cytokinetic data are significantly different (S phase and RNA-I; p less than 0.001) than previously reported for the L1 and L2 ALL. Abnormal DNA stemlines were found in cases with no detected cytogenetic abnormalities. This study confirms that L3 ALL is characterized by significantly increased proliferation and provides a means for a flow cytometric identification of this subtype as compared to L1 and L2 ALL.

B-cell acute lymphocytic leukemia in HIV-antibody-positive patients

B-cell non-Hodgkin lymphoma (NHL) has been well described in association with human immunodeficiency virus (HIV) and the acquired immunodeficiency syndrome (AIDS). Many of these lymphomas are of the diffuse, aggressive, subtype B-cell NHL, including Burkitt and Burkitt-like lymphoma. Recently, there have been reports of B-cell acute lymphocytic leukemia (ALL), Burkitt type, in patients who were either HIV antibody-positive or at high risk for AIDS. We have seen three cases of B-cell ALL, Burkitt type, and herein describe their clinical and laboratory characteristics. All patients were HIV antibody-positive. Since stage IV Burkitt lymphoma in blood phase and B-cell ALL, Burkitt type, represent a continuum of the same disease, and since it is also an aggressive B-cell malignancy, we suggest that B-cell ALL, Burkitt type, in HIV antibody-positive patients should support the diagnosis of AIDS.

Hybrid acute leukemia in an HIV-antibody-positive patient

Although the great majority of acute leukemias have been designated as being of lymphocytic or myelocytic origin, recent reports have described elements of both in some patients. We describe here the first case of hybrid acute leukemia in an HIV-antibody-positive patient as well as the first hybrid involving B-cell (Burkitt) acute lymphocytic leukemia and acute myelomonocytic leukemia proven by cytochemical, immunologic, and cytogenetic methods. This case illustrates the increasingly complex difficulties in the diagnosis and treatment of AIDS-related malignancies.

High-degree abnormalities of nuclear DNA distribution in SIg negative acute lymphoblastic leukemia with vacuolated blasts

Among 65 consecutive patients with untreated adult acute lymphoblastic leukemia (ALL), six had peculiar clinical and cytologic features. Bone marrow and circulating blasts were large and showed prominent vacuolization, with variable degree of granular periodic acid-Schiff positivity in the cytoplasm. All patients had marked spleen and liver enlargement with cholestasis and without either lymph node or central nervous system disease. They achieved complete response to chemotherapy, and their median survival was longer than 12 months. Blast cells were studied for immunologic markers, propidium iodide flow cytofluorometric DNA content, and in vitro tritiated thymidine labeling index (3H-TdR LI). These showed a "null" phenotype in two cases, contained intracytoplasmic immunoglobulins (Cy mu) in two and were positive for CALL and Ia antigens in two others (one of which also contained Cy mu). Surface immunoglobulins (SIg) were found on less than 12% of cells, and T-cell markers were absent. In five cases, one or two stem lines with highly abnormal modal DNA content were found to coexist with diploid blasts. The 3H-TdR LI was high (8.5%-15.5%). Abnormal cell lines, after being cleared by chemotherapy, were found again at relapse. Additional cell lines appeared during the course of the disease in one patient, having different sensitivity to cytostatics. These cases of ALL apparently derive from B-cells not yet expressing SIg and have an exceptionally high incidence of aneuploid cell lines.

Immunological and cytogenetic studies in two cases of B-cell acute lymphoblastic leukemia (Burkitt's type)

Immunological and cytogenetic studies were performed on two patients who presented with L-3 acute lymphocytic leukemia (Burkitt-type). Surface marker studies showed that both had B-cell leukemias. The blast cells in Case 1 expressed monoclonal IgM kappa surface immunoglobulin and in Case 2, IgG kappa. In the first case, cytogenetic analysis of bone marrow revealed the presence of a rare variant translocation involving the short arm of chromosome 2 and the long arm of chromosome 8 in all the metaphases examined. This is the second report of such a translocation in Burkitt's leukemia. The 8;14 translocation reported in classical Burkitt's lymphoma and other B-cell lymphomas was present in all the bone marrow metaphases in the second case.

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.