Myeloblasts, Cerebrospinal Fluid — Manual Number Fraction
A manual laboratory count of myeloblasts, immature white blood cells, in cerebrospinal fluid. It may help evaluate suspected leukemia or lymphoma involving the nervous system.
["This test measures the proportion of cerebrospinal-fluid cells that are myeloblasts, which can increase when leukemia involves the nervous system."]
Key facts at a glance
- LOINC
- 55436-0
- Short code
- Myeloblasts NFr CSF Manual
- Synonyms
- Myeloblasts NFr CSF Manual
- Category
- liver
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- manual-count
- CPT
- 84484
- SNOMED
- 302774002
- Specimen volume
- 1-2 mL
- Stability
- Immediate analysis required, Refrigerated: 1h
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
What is this test?
Myeloblasts are immature white blood cells that normally develop into granulocytes, a group that includes neutrophils. This test examines cerebrospinal fluid to determine whether myeloblasts are present and what proportion of the cells they represent.
Why might I need this test?
This test may be ordered when cerebrospinal fluid is being evaluated for suspected leukemia, lymphoma, or another cause of abnormal cells in the central nervous system. It can also help monitor people with a blood cancer for involvement of the cerebrospinal fluid.
How is the test performed?
A laboratory technologist examines a cerebrospinal-fluid specimen under a microscope and manually identifies and counts myeloblasts among the cells present. The result is reported as the number or proportion of myeloblasts, often with other cerebrospinal-fluid findings.
How do I prepare for the test?
Cerebrospinal fluid is usually collected by lumbar puncture, so preparation depends on your clinician's instructions. Fasting is generally not required, but you should tell the clinician about blood-thinning medicines, infection symptoms, medicines that may cause sedation, and any prior spinal surgery or spinal problems.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Detecting myeloblasts in cerebrospinal fluid may indicate the presence of leukemic or other immature cells in the central nervous system. The finding should be interpreted with the blood counts, other cerebrospinal-fluid tests, imaging, and sometimes flow-cytometry or cytology results. A sample with too few cells may be less reliable, and the laboratory may comment on specimen adequacy.
Short name
CSF myeloblast fraction
Frequently asked questions
What does a positive result mean?
Is this the same as a complete blood count?
How is cerebrospinal fluid collected?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 17, 2026. · Read our editorial policy