24 Body fluids
This atlas addresses primarily the elements of fluids that are observable through a microscope. For a more detailed explanation of body fluids, consult a hematology or urinalysis textbook that includes a discussion of body fluids, such as Hematology: Clinical Principles and Applications* or Fundamentals of Urine and Body Fluid Analysis.†
When preparing cytocentrifuge slides, a consistent amount of fluid should be used to generate a consistent yield of cells. Usually two to six drops of fluid are used depending on the nucleated cell count. Five drops of fluid will generally yield enough cells to perform a 100-cell differential if the nucleated cell count is at least 3/mm3. For very high counts, a dilution with normal saline may be made. The area of the slide where the cell button will be deposited should be marked with a wax pencil in case the number of cells recovered is small and difficult to locate (Figure 24-1). Alternatively, specially marked slides can be used.
FIGURE 24–1A Wright-stained cytocentrifuge slide demonstrating a concentrated button of cells within the marked circle.
There may be some distortion of cells as a result of centrifugation or when cell counts are high. Dilutions with normal saline should be made before centrifugation to minimize distortion when nucleated cell counts are high. When the red blood cell (RBC) count is extremely high (more than 1 million), the slide should be made in the same manner as the peripheral blood smear slide (see Chapter 1). However, the examination of the smear should be performed at the end of the slide rather than the battlement pattern used for blood smears. This is because the larger, and usually more significant, cells are likely to be pushed to the end of the slide.
Any cell that is seen in the peripheral blood may be found in a body fluid in addition to cells specific to that fluid (e.g., mesothelial cells, macrophages, tumor cells). However, the cells look somewhat different than in peripheral blood, and some in vitro degeneration is normal. The presence of organisms, such as yeast and bacteria, should also be noted (see Figures 24-12 to 24-14).
Cells commonly seen in cerebrospinal fluid
Comments:
Small numbers of neutrophils, lymphocytes, and monocytes may be seen in normal CSF.
Increased numbers of neutrophils are associated with bacterial meningitis; early stages of viral, fungal, and tubercular meningitis; intracranial hemorrhage; intrathecal injections; central nervous system (CNS) infarct; malignancy; or abscess.
Increased numbers of lymphocytes and monocytes are associated with viral, fungal, tubercular and bacterial meningitis, and multiple sclerosis.
Cells sometimes found in cerebrospinal fluid
Reactive lymphocytes (Figure 24-5) are associated with viral meningitis and other antigenic stimulation. The cells will vary in size; nuclear shape may be irregular and cytoplasm may be scant to abundant with pale to intense staining characteristics. (See description of reactive lymphocytes, Figure 14-7.)
Blasts in the CSF may have some of the characteristics of the acute lymphoblastic leukemia (ALL) blasts seen in the peripheral blood (Figure 24-6; see Chapter 16). It is not unusual for ALL to have CNS involvement, and blasts may be present in the CSF before being observed in the peripheral blood.
Cells sometimes found in cerebrospinal fluid after central nervous system hemorrhage
1.Neutrophils and macrophages—appear within 2 to 4 hours
2.Erythrophages—identifiable from 1 to 7 days
3.Hemosiderin and siderophages—observable from 2 days to 2 months
Macrophage with engulfed RBCs. RBCs are digested by enzymatic activity within the macrophage. The digestion process causes the RBCs to lose color and to appear as vacuoles within the cytoplasm of some macrophages.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
