Leukemic cellular thrombi in pulmonary blood vessels. Subleukemic myelogenous leukemia following chloramphenicol-induced aplastic anemia

Phosphatidylserine index as a marker of the procoagulant phenotype of acute myelogenous leukemia cells

Patients with acute myelogenous leukemia (AML) are at risk for thrombotic complications. Risk to develop thrombosis is closely tied to leukemia subtype, and studies have shown an association between leukocytosis and thrombosis in AML M3. We evaluated the relative roles of cell count and the surface expression of tissue factor (TF) and phosphatidylserine (PS) in the procoagulant phenotype of AML cell lines. The TF-positive AML M3 cell lines, NB4 and HL60, and AML M2 cell line, AML14, exhibited both extrinsic tenase and prothrombinase activity in a purified system and promoted experimental thrombus formation. In contrast, the TF-negative AML cell line, HEL, exhibited only prothrombinase activity and did not affect the rate of occlusive thrombus formation. In plasma, NB4, HL60 and AML14 shortened clotting times in a cell-count, PS- and TF-dependent manner. Exposure of cultured NB4, HL60, and AML14 cells to the chemotherapeutic agent daunorubicin increased their extrinsic tenase activity and PS expression. Clot initiation time inversely correlated with logarithm of PS index, defined as the product of multiplying leukocyte count with cell surface PS exposure. We propose that leukemia cell PS index may serve as a biomarker for procoagulant activity.

Hypoplastic acute leukemia: review of 70 cases with multivariate regression analysis

Between 1971 and 1984, 22 of 190 adult patients (11.6 per cent) with acute leukemia seen at the University of Arizona had hypocellular acute leukemia (HAL), defined as lymphoblasts or myeloblasts (plus atypical promyelocytes) of greater than or equal to 30 per cent, but marrow cellularity of the core biopsy or clot section of less than or equal to 50 per cent based on a 1000 point count. These 22 patients with HAL plus the 48 previously published patients with well documented HAL (combined series of 70 patients) were evaluated in detail with multivariate analysis. The median leukocyte count was 2700/microL, hemoglobin of 8.2 g/dl, and platelet count 63,000/microL. Circulating blasts were noted in 27 of 52 patients (52 per cent). Twenty-seven of 34 patients (79 per cent) had abnormal cytogenetics. The overall median survival was 8 months (range: 0.1-48). The median survival for the 22 patients managed with supportive care alone was 4 months, 6 months for the 16 patients treated with non-aggressive induction therapy, and 13 months for the 32 patients treated with aggressive induction therapy (p less than 0.02 versus other categories). Multivariate analysis confirmed that aggressive induction therapy was a major favourable prognostic factor (p = 0.016). Multivariate analysis of the aggressively induced patients revealed that younger patients (less than or equal to 65; p = 0.04) and patients with no AHD (p = 0.09) lived longer. Thus, aggressive remission induction can be attempted in HAL and appears to contribute to prolonged survival especially under age 65 years.

Erythroleukemia following drug induced hypoplastic anemia

Three patients with drug-induced hypoplastic anemia terminating 2 to 6 years after presentation with erythroleukemia are described. All were treated for prolonged periods with androgen and corticosteroid and two of the patients showed apparent dependence on this therapy for optimal hematologic status. The leukemic phase was heralded by loss of this dependence and development of sideroblastic dyserythropoiesis with progression to bizarre erythroid hyperplasia and fatal cytopenia. The exact relationship between androgen and corticosteroid therapy and the erythroleukemia remains speculative.

Carcinocythemia (carcinoma cell leukemia) due to metastatic carcinoma of the breast: report of a case

A patient with a 17-year course of metastatic lobular carcinoma of the breast is described who developed large numbers of circulating carcinoma cells which were easily detectable in several routine peripheral blood smears shortly before death. This rare complication of carcinoma has been called "carcinocythemia." Carcinocythemia is probably due to widespread infiltration of many bone marrow sites and may also be related to splenectomy, which may impair reticuloendothelial clearance of circulating tumor cells. The differential diagnosis of carcinocythemia from superimposed acute myelogenous leukemia, which can complicate radiotherapy and chemotherapy for the primary tumor, is discussed. Cytomorphology, histochemistry, and electron microscopy of abnormal circulating cells should aid in the distinction of these two processes.