- Progressive proliferation of abnormal leukocytes found in hemopoietic tissues, other organs, and usually in the blood in increased numbers. L. is classified by the dominant cell type, and by duration from onset to death. This occurs in acute l. within a few months in most cases, and is associated with acute symptoms including severe anemia, hemorrhages, and slight enlargement of lymph node s or the spleen. The duration of chronic l. exceeds one year, with a gradual onset of symptoms of anemia or marked enlargement of spleen, liver, or lymph node s. SYN: leukocytic sarcoma. [leuko- + G. haima, blood]- acute promyelocytic l. l. presenting as a severe bleeding disorder, with infiltration of the bone marrow by abnormal promyelocytes and myelocytes, a low plasma fibrinogen, and defective coagulation.- basophilic l., basophilocytic l. a form of granulocytic l. in which there are unusually great numbers of basophilic granulocytes in the tissues and circulating blood; in some instances, the immature and mature basophilic forms may represent from 40 to 80% of the total numbers of white blood cells. SYN: mast cell l..- chronic myelocytic l. a heterogeneous group of myeloproliferative disorders that may evolve into acute l. in late stages ( i.e., blast crisis.) SYN: chronic granulocytic l., chronic myelogenous l., chronic myeloid l..- l. cutis yellow-brown, red, blue-red, or purple, sometimes nodular lesions associated with diffuse infiltration of leukemic cells in the skin; the involvement may be diffuse and generalized, i.e., so-called universal l. cutis, or it may be localized.- eosinophilic l., eosinophilocytic l. a form of granulocytic l. in which there are conspicuous numbers of eosinophilic granulocytes in the tissues and circulating blood, or in which such cells are predominant; in chronic disease of this type, the total white blood cell count may be as high as 200,000–250,000 per mm3, with as many as 80 or 90% being eosinophils, chiefly adult forms.- granulocytic l. a form of l. characterized by an uncontrolled proliferation of myelopoietic cells in the bone marrow and in extramedullary sites, and the presence of large numbers of immature and mature granulocytic forms in various tissues (and organs) and in the circulating blood; the total count may range from 1000 (aleukemic variety) to several hundred thousand per cu mm. The predominant cell is usually of the neutrophilic series, but, in a few instances, eosinophilic or basophilic granulocytes, or even megakaryocytes, may represent the chief form; early in granulocytic l., the circulating blood may contain excessive numbers of all of the granulocytic forms. SYN: leukemic myelosis (1), myelocytic l., myelogenic l., myelogenous l., myeloid l..- hairy cell l. a rare, usually chronic disorder characterized by proliferation of hairy cells in reticuloendothelial organs and blood.- leukemic l. an obsolete redundant term sometimes used to emphasize the occurrence of abundant numbers of leukemic cells in the circulating blood; this classic form of l. is usually termed simply l..- leukopenic l. a form of lymphocytic, granulocytic, or monocytic l. in which the total number of white blood cells in the circulating blood is in the normal range, or may be diminished to various levels that are significantly less than normal.- lymphoblastic l. acute lymphocytic l. in which the abnormal cells are chiefly (or almost totally) blast forms of the lymphocytic series, or in which unusually large numbers of the immature forms occur in association with adult lymphocytes.- lymphocytic l. a variety of l. characterized by an uncontrolled proliferation and conspicuous enlargement of lymphoid tissue in various sites ( e.g., lymph node s, spleen, bone marrow, lungs), and the occurrence of increased numbers of cells of the lymphocytic series in the circulating blood and in various tissues and organs; in chronic disease, the cells are adult lymphocytes, whereas conspicuous numbers of lymphoblasts are observed in the more acute syndromes. SYN: lymphatic l., lymphoid l..- megakaryocytic l. an unusual form of myelopoietic disease that is characterized by a seemingly uncontrolled proliferation of megakaryocytes in the bone marrow, and sometimes by the presence of a considerable number of megakaryocytes in the circulating blood. When bone marrow is examined at various intervals in some instances of chronic myelocytic l., the proliferation of megakaryocytes is more prominent than that of the granulocytes; at such times, the circulating blood may contain megakaryocytes or fragments of megakaryocytic nuclei and cytoplasm, or both, amounting to as much as 5 or 6% of the total number of leukocytes.- meningeal l. infiltration of the meninges by leukemic cells, a common occurrence in relapse following systemic administration of chemotherapeutic agents to l. patients.- micromyeloblastic l. a form of myelocytic l. in which relatively large proportions of micromyeloblasts are found in the circulating blood and in bone marrow and other tissues.- mixed l., mixed cell l. term infrequently used as a designation for granulocytic l., thereby emphasizing the occurrence of different types of cells in the myeloid series ( i.e., neutrophilic, eosinophilic, and basophilic granulocytes), in contrast to the comparatively monotonous pattern observed in lymphocytic and monocytic l..- monocytic l. a form of l. characterized by large numbers of cells that can be definitely identified as monocytes, in addition to larger, apparently related cells formed from the uncontrolled proliferation of the reticuloendothelial tissue; l. in which these two types of cells seem to “overrun” the usual sites of the reticuloendothelial system, and occur in conspicuous numbers in the circulating blood, is frequently referred to as the Schilling type of monocytic l., or sometimes as true monocytic l. The disease runs an acute or subacute course in older persons, and is characterized by swelling of gums, oral ulceration, bleeding in skin or mucous membranes, secondary infection, and splenomegaly.- myeloblastic l. a form of granulocytic l. in which there are large numbers of myeloblasts in various tissues (and organs) and in the circulating blood; the immature forms may amount to 30–60% (or even a greater proportion) of the increased total number of white blood cells. Used synonymously with acute granulocytic l.. SYN: leukemic myelosis (2).- myelomonocytic l. a variant of granulocytic l. with monocytosis in the peripheral blood. SYN: Naegeli type of monocytic l..- natural killer cell l. a l. originating from cells of natural killer cell origin; often associated with the presence of monoclonal Epstein-Barr virus infecting tumor cells; usually indicates a leukemic subtype of poor prognosis.- neutrophilic l. an unusual form of chronic granulocytic l. in which the greatly increased number of leukocytes in the circulating blood are mature polymorphonuclear neutrophils, with virtually no young or immature granulocytes being observed.- plasma cell l. an unusual disease characterized by leukocytosis and other signs and symptoms that are suggestive of l., in association with diffuse infiltrations and aggregates of plasma cells in the spleen, liver, bone marrow, and lymph node s, and the presence of considerable numbers of plasma cells in the circulating blood; the total number of leukocytes in the latter may range from normal levels to 80,000 or 90,000/mm3, and 5–90% may be plasma cells; multiple myelomas are observed in some examples of plasma cell l., but discrete nodules are not formed in bone. Although there are other clinicopathologic differences in the two conditions, they may be phases of the same basic process.- polymorphocytic l. granulocytic l., especially any variety in which the predominant cells are mature, segmented granulocytes.- Rieder cell l. a special form of acute granulocytic l. in which the affected tissues and the circulating blood contain relatively large numbers of atypical myeloblasts ( i.e., Rieder cells) that have the usual, faintly granular, immature type of cytoplasm, and a bizarre, comparatively mature nucleus with several wide and deep indentations (suggestive of lobulation).- splenic l. a form of l. in which there is an unusually great degree of enlargement of the spleen, as observed frequently in chronic granulocytic l..- stem cell l. a form of l. in which the abnormal cells are thought to be the precursors of lymphoblasts, myeloblasts, or monoblasts. SYN: embryonal l..- subleukemic l. a form of l. in which abnormal cells are present in the peripheral blood, but the total leukocyte count is not elevated. SYN: hypoleukemia, leukopenic myelosis, subleukemic myelosis, subleukemia.
* * *leu·ke·mia lü-'kē-mē-ə also leu·ce·mia lü-'kē-also lü-'sē- or chiefly Brit leu·kae·mia also leu·cae·mia n an acute or chronic disease of unknown cause in humans and other warm-blooded animals that involves the blood-forming organs, is characterized by an abnormal increase in the number of white blood cells in the tissues of the body with or without a corresponding increase of those in the circulating blood, and is classified according to the type of white blood cell most prominently involved see ACUTE LYMPHOBLASTIC LEUKEMIA, ACUTE MYELOGENOUS LEUKEMIA, CHRONIC LYMPHOCYTIC LEUKEMIA, CHRONIC MYELOGENOUS LEUKEMIA, FELINE LEUKEMIA, LYMPHOBLASTIC LEUKEMIA, LYMPHOCYTIC LEUKEMIA, MONOCYTIC LEUKEMIA, MYELOGENOUS LEUKEMIA, PROMYELOCYTIC LEUKEMIA
* * *leu·ke·mia (loo-keґme-ə) [leuk- + -emia] a progressive, malignant disease of the blood-forming organs, characterized by distorted proliferation and development of leukocytes and their precursors in the blood and bone marrow. It is classified according to degree of cell differentiation as acute or chronic (terms no longer referring to duration of disease), and according to predominant type of cell involved as myelogenous or lymphocytic. leukemic adj
Medical dictionary. 2011.