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Cerebrospinal Fluid Myelocyte Count (Manual Differential)

Published: August 9, 2026Updated: August 16, 2026

This test measures the number of immature white blood cells called myelocytes in your cerebrospinal fluid (CSF). These cells are part of your immune system and can help identify certain conditions affecting the brain or spinal cord.

Quick summary

["Myelocyte counts in CSF may help diagnose or monitor blood disorders or infections in the central nervous system."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
30368-5
Short code
Myelocytes NFr CSF Manual
Synonyms
Myelocytes NFr CSF Manual
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
manual-count
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Doctors may order this test if you have symptoms like headaches, neck stiffness, confusion, or unexplained fatigue that could suggest an infection, inflammation, or blood disorder in your brain or spinal cord. It may also be part of a broader evaluation for conditions like leukemia or other hematologic diseases.

What Does the Test Involve?

A small amount of CSF is collected through a procedure called a lumbar puncture (spinal tap). The sample is then examined under a microscope to count myelocytes among other white blood cells.

Sample Collection and Preparation

The test uses cerebrospinal fluid collected directly from your spine. No special preparation is needed, but you may be asked to empty your bladder beforehand.

What to Expect After the Test

After the procedure, you may feel mild soreness or discomfort at the injection site. You’ll need to lie flat for a short time to prevent any spinal fluid leakage. Most people return to normal activities quickly.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated myelocyte counts in CSF may indicate conditions such as leukemia, infections, or other hematologic disorders. Abnormal results can guide treatment decisions, such as further blood tests, imaging, or targeted therapies. Always discuss results with your healthcare provider.

Short name

Myelocyte count in CSF

Frequently asked questions

What causes abnormal myelocyte counts in CSF?
Abnormal myelocyte counts in CSF can result from blood cancers (like leukemia), infections (such as meningitis), or inflammatory conditions affecting the central nervous system. These cells are typically not present in healthy CSF, so their presence often signals an underlying issue.
How long does it take to get results?
Results are usually available within 1–2 business days, depending on lab processing times. Your healthcare provider will discuss the findings with you during your follow-up visit.
Can I eat or drink before this test?
No special diet is required before this test. However, avoid caffeine or heavy meals 2 hours before the procedure to minimize discomfort during the lumbar puncture.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy