Leukoerythroblastosis can be defined as the presence of both immature WBCs (metamyelocytes or earlier cells) and nucleated RBCs in the peripheral blood smear. Although the relative frequency of etiologies is different in different reports, approximately 25%-30% of patients with leukoerythroblastosis have metastatic tumor in the bone marrow, about 20% have leukemia, about 10% have myeloid […]
Neutropenia is usually defined as a WBC count less than 4,000/mm3. Some conditions associated with neutropenia include (1) conditions associated with pancytopenia, such as megaloblastic anemia, aplastic anemia, acute or aleukemic leukemia, hypersplenism of varying etiology (e.g., cirrhosis, systemic lupus, Gaucher’s disease), and paroxysmal nocturnal hemoglobinuria, (2) drug-induced neutropenia (agranulocytosis), (3) certain infections, such as […]
Lymphocytosis is most commonly associated with a normal or a decreased total WBC count. The most common etiology is viral infection. The lymphocytosis seen in the majority of viral infections is actually a relative type due to a decrease in granulocytes while total (absolute) lymphocyte numbers remain constant. The same phenomenon is found in Addison’s […]
Leukemoid reaction is usually defined as a nonleukemic WBC count more than 50,000/mm3 (50 х 109/L) or a differential count with more than 5% metamyelocytes or earlier cells. It is basically a more severe or pronounced form of ordinary nonneoplastic granulocyte reaction. Some conditions associated with leukemoid reaction are severe bacterial infections, severe toxic states […]
White blood cells (WBCs, leukocytes) form the first line of defense of the body against invading microorganisms. Neutrophils and monocytes respond by phagocytosis; lymphocytes and plasma cells primarily produce antibodies. In addition to a nonspecific response to bacterial or viral infection, there are alterations in the normal leukocyte blood picture that may provide diagnostic clues […]
