Dictionary

lightening See engagement.

lightheadedness A feeling that one is about to faint. Lightheadedness is medically distinct from dizziness, unsteadiness, and vertigo. See also dizziness; unsteadiness; vertigo.

lights, flashing A sensation that is created when the clear, jelly-like substance that fills the middle of the eye (vitreous humor) shrinks and tugs on the retina. These flashes of light can appear off and on for several weeks or months. As a person ages, flashes are likely to occur increasingly often. Flashes usually do…

limb An arm or a leg.

leukemia, blastic phase of A stage in chronic myeloid leukemia in which 30 percent or more of the cells in the bone marrow or blood are the malignant blast cells. See also leukemia, chronic myeloid.

leukemia, chronic lymphocytic The most common form of leukemia in adults, in which lymphocytes look fairly normal but are not fully mature and do not function correctly against infection. The malignant cells are found in blood and bone marrow, collect in and enlarge the lymph nodes, and may crowd out other blood cells in the…

leukemia, chronic myelogenous See leukemia, chronic myeloid.

leukemia, chronic myeloid A malignant disease involving the white blood cells belonging to the myeloid line that is due to a chromosome rearrangement called the Philadelphia (or Ph) chromosome translocation. Abbreviated CML. CML has several phases that succeed one another. In the first phase, the chronic phase, there are few blast cells in blood and…

leukemia, chronic phase of A stage in chronic myeloid leukemia in which there are few blast cells in the blood or bone marrow and few, if any, symptoms. See also leukemia, chronic myeloid.

leukemia, hairy cell A rare type of chronic leukemia in which the abnormal white blood cells appear to be covered with tiny hairs when examined microscopically. The hairy cells are malignant B lymphocytes. There may be too few normal blood cells of all types because of an excess of leukemic cells in the bone marrow….

leukemia, lymphocytic Cancer of blood cells that are precursors of lymphocytes. The two major types of lymphocytic leukemia are acute lymphoblastic leukemia (ALL) and chronic lymphocytic leukemia (CML). Also known as lymphoid leukemia.

leukemia, myeloid Cancer of the blood cells of the myeloid line. The two major types of myeloid leukemia are acute myeloid leukemia (AML) and chronic myeloid leukemia (CML). Also known as myelogenous leukemia and nonlymphocytic leukemia.