Ch 21 Nonmalignant Disorders of Leukocytes: Granulocytes and Monocytes

Sea-blue histiocytosis syndrome

rare inherited disorder characterized by splenomegaly and thrombocytopenia. Sea blue-staining macrophages are found in the liver, spleen, and bone marrow. The cell is large (in diameter) with a dense eccentric nucleus and cytoplasm that contains blue or blue-green granules. In most patients, the course of the disease is benign.

Leukoerythroblastic reaction

response characterized by the presence of nucleated erythrocytes and a shift to the left in neutrophils in the peripheral blood; often associated with myelophthisis.

Leukemoid reaction

transient, responsive condition resulting from certain types of infections or tumors characterized by an increase in the total leukocyte count to more than 25×109/L and a shift to the left in leukocytes (usually granulocytes).

Pelger-Huët anomaly (PHA)

unusually acquired condition in which neutrophils display a hyposegmented nucleus. Unlike the real Pelger-Huët anomaly, this cell's nucleus contains a significant amount of euchromatin and stains more lightly. A critical differentiation point is that all neutrophils are equally affected in the genetic form of Pelger-Huët anomaly, but only a fraction are hyposegmented cells in the acquired state. It is associated with MDS and MPD and can also be found after treatment for leukemias.

Morulae

basophilic, irregularly shaped granular, cytoplasmic inclusions found in leukocytes in an infectious disease called ehrlichiosis.

Leukocytosis

increase in WBCs in the peripheral blood; WBC count >11.0×109/L.

Monocytosis

increase in the concentration of circulating white blood cells known as monocytes (>0.8×109/L).

Eosinophilia

increase in the concentration of eosinophils in the peripheral blood (>0.5×109/L) associated with parasitic infection, allergic conditions, hypersensitivity reactions, cancer, and chronic inflammatory states.

Pseudo-neutrophilia

increase in the concentration of neutrophils in the peripheral blood (>7.0×109/L) occurring as a result of cells from the marginating pool entering the circulating pool. The response is immediate but transient. This redistribution of cells accompanies vigorous exercise, epinephrine administration, anesthesia, convulsion, and anxiety states. Also called immediate or shift neutrophilia.

Reactive neutrophilia

increase in the concentration of peripheral blood neutrophils (>7.0×109/L) as a result of reaction to a physiologic or pathologic process.

Neutrophilia

increase in white blood cells >7.0×109/L. It can be seen in bacterial infections, inflammation, metabolic intoxication, drug intoxication, and tissue necrosis.

Basophilia

increased concentration of circulating basophils.

Toxic granules

large, dark blue-black primary particle in the cytoplasm of neutrophils present in certain infectious states; usually seen in conjunction with Döhle bodies.

Demargination

movement of neutrophils that are loosely attached to endothelial cells lining the blood vessels into the circulation; can cause a pseudoneutrophilia.

Döhle body

oval aggregate of rough endoplasmic reticulum that stains light gray blue (with Romanowsky stain) found within the cytoplasm of neutrophils and eosinophils; associated with severe bacterial infection, pregnancy, burns, cancer, aplastic anemia, and toxic states.

Hypereosinophilic syndrome (HES)

persistent blood eosinophilia >1.5×109/L with tissue infiltration, absence of clonal genetic aberrations, and no apparent cause of the increase in eosinophils.

Agranulocytosis

absence of white blood cells in the peripheral blood.

Egress

action of going out or exiting; describes the exit of blood cells from the blood to the tissue.

Shift to the left or left shift

appearance of increased numbers of immature leukocytes in the peripheral blood.

Leukopenia

decrease in leukocytes <4.5×109/L.

Neutropenia

decrease in neutrophils (<1.8×109/L).

Mastocytosis

disorder caused by heterogeneous group of mast cell diseases characterized by the abnormal proliferation of mast cells in one or more organ systems. Two major groups of mast cell disorders are cutaneous and systemic. It is suggested that mast cell disorders be classified as myeloproliferative disorders.

Monocytopenia

disorder characterized by a decrease in the concentration of a class of circulating white blood cells known monocytes (<0.1×109/L).

Myelophthisis

displacement of normal hematopoietic tissue in bone marrow by fibrosis, leukemia, or metastatic cancer cells.

Lysosomal storage disorders

disruption of membrane-bound sac characterized by defects in various enzymes (including glucosidases, lipases, proteases, and nucleases) that are involved in degradative processes leading to the accumulation of either nondegraded substrates or catabolic products that are unable to be transported out of the lysosome.