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Introduction ⬇

CSF for cytology is obtained by lumbar puncture and examined for the presence of abnormal cells and for an increase or decrease in the normally present cell population. Most laboratory procedures for study of CSF involve an examination of the leukocytes and a leukocyte count; chemical and microbiologic studies are also done. Cell studies of the CSF also have been used to identify neoplastic cells. These studies have been especially helpful in diagnosis and treatment of the different phases of leukemia. The nature of neoplasia is such that for tumor cells to exfoliate, they must actually invade the CSF circulation and enter such areas as the ventricle wall, the choroid plexus, or the subarachnoid space.

Procedure ⬆ ⬇

  1. Obtain four specimens of at least 1–3 mL each by lumbar puncture (see Chapter 5).

  2. Generally, only one specimen of 1–3 mL goes to the cytology laboratory. Other tubes are sent to different laboratories for examination.

  3. Label the specimens with the patient’s name, date and time of collection, and test(s) ordered.

  4. Send the sample immediately to the cytology laboratory for processing.

Procedural Alert

The laboratory should be given adequate warning that a CSF specimen is being delivered. Time is a crucial factor; cells begin to disintegrate if the sample is kept at room temperature for >1 hour

Clinical Implications ⬆ ⬇

  1. CSF abnormalities may indicate:

    1. Malignant gliomas that have invaded the ventricles or cortex of the brain: leukocytes, 150/mm3 or 150 × 109 cells/L

    2. Ependymoma (neoplasm of differentiated ependymal cells) and medulloblastoma (a cerebellar tumor) in children

    3. Seminoma and pineoblastoma (tumors of the pineal gland)

    4. Secondary carcinomas:

      1. Secondary carcinomas metastasizing to the central nervous system have multiple avenues to the subarachnoid space through the bloodstream.

      2. The breast and lung are common sources of metastatic cells exfoliated in the CSF. Infiltration of acute leukemia is also common.

    5. Central nervous system leukemia

    6. Fungal forms:

      1. Congenital toxoplasmosis: leukocytes, 50–500/mm3 or 50–500 × 109 cells/L (mostly monocytes present)

      2. Coccidioidomycosis: leukocytes, 200/mm3 (200 × 109 cells/L)

    7. Various forms of meningitis:

      1. Cryptococcal meningitis: leukocytes, 800/mm3 L (lymphocytes are more abundant than polynuclear neutrophilic leukocytes)

      2. Tuberculous meningitis: leukocytes, 25–1000/mm3 or 25–1000 × 109 cells/L (mostly lymphocytes present)

      3. Acute pyogenic meningitis: leukocytes, 25–1000/mm3 or 25–1000 × 109 cells/L (mostly polynuclear neutrophilic leukocytes present)

    8. Meningoencephalitis (primary amebic meningoencephalitis):

      1. Leukocytes, 400–21,000/mm3 or 400–21,000 × 109 cells/L.

      2. Red blood cells are also found.

      3. Wright stain may reveal amebas.

    9. Hemosiderin-laden macrophages, as in subarachnoid hemorrhage

    10. Lipophages from central nervous system destructive processes

  2. Characteristics of neoplastic cells:

    1. Marked increase in size (usually sarcoma and carcinoma)

    2. Exfoliated cells tend to be more polymorphic as the neoplasm becomes increasingly malignant

Interventions ⬆ ⬇

Pretest Patient Care

  1. Explain the procedure to the patient (Chapter 5). Tell the patient that a local anesthetic agent will be used. Ask whether the patient has a history of reacting to local anesthetic agent. Warn the patient that the procedure may be uncomfortable and that immobilization is extremely important. Instruct the patient to breathe normally and not to hold the breath.

  2. Provide the patient with physical and emotional support during the procedure.

  3. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

Clinical Alert

Contraindications for a lumbar puncture include an uncooperative patient, skin infection near the site of needle insertion, and uncorrected coagulopathy

Posttest Patient Care

  1. Place the patient in a supine position. Keep the head of the bed flat for 4–8 hours as ordered; if headache occurs, elevate the feet 10°–15° above the head. Assist and teach the patient to turn and deep breathe every 2–4 hours. Monitor blood pressure, pulse, and respiration every 15 minutes four times, then every hour four times, and then as ordered. Assess for and control pain as ordered and observe the site of puncture for redness, swelling, or drainage; report any symptoms to the healthcare provider.

  2. Review test results; report and record findings. Modify the nursing care plan as needed.

  3. Follow guidelines in Chapter 1 for safe, effective, and informed posttest care.

Interfering Factors ⬆ ⬇

The lumbar puncture can occasionally cause contamination of the specimen with squamous epithelial cells or spindly fibroblasts.

Reference Values ⬆

Normal

Total cell count, adult: 0–10/mm3 or 0–10 × 109 cells/L (all mononuclear cells)

Total cell count, infant: 0–20/mm3 or 0–20 × 109 cells/L

Negative for neoplasia

A variety of normal cells may be seen. Large lymphocytes are most common. Small lymphocytes are also seen, as are elements of the monocytomacrophage series.

The CSF of a healthy person should be free of all pathogens.

Negative for blood