Skip to content

Lymphoblasts, Bone Marrow — Manual Count

Published: August 9, 2026Updated: August 17, 2026

A manual count of lymphoblasts in a bone marrow sample, used to evaluate the number of immature lymphoid cells present.

Quick summary

["This test measures the burden of lymphoblasts in bone marrow, which can help assess and monitor certain lymphoid blood cancers."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
50724-4
Short code
Lymphoblasts NFr Mar Manual
Synonyms
Lymphoblasts NFr Mar Manual
Category
liver
Sample
serum
Container
Red-top tube (SST)
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
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

This test counts lymphoblasts, which are immature white blood cells of the lymphoid lineage, in a bone marrow sample. The cells are examined under a microscope as part of a bone marrow evaluation.

Why might I need this test?

It may be used to investigate unexplained changes in blood counts, evaluate suspected acute lymphoblastic leukemia or lymphoma, and monitor response to treatment. Results are usually interpreted with other laboratory and clinical findings.

How is the test performed?

A clinician obtains a small bone marrow sample, usually by aspiration. Laboratory professionals prepare and stain the sample, then manually identify and count lymphoblasts under a microscope.

How do I prepare for the test?

No specific food or medicine preparation is usually required. Follow your clinician's instructions, tell the care team about medicines that affect blood counts, and ask whether local anesthesia or sedation will be used.

Reference range

Adult: 10-40 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Bone Marrow Lymphoblast Count

Frequently asked questions

What is a lymphoblast?
A lymphoblast is an immature blood cell that can develop into a lymphocyte. When these cells accumulate in the bone marrow, they may interfere with normal blood-cell production.
Does this test alone diagnose leukemia?
No. The result is interpreted together with symptoms, blood counts, other marrow findings, flow cytometry, and sometimes genetic testing.
Is a bone marrow test painful?
It may cause brief discomfort during needle insertion, especially where the sample is taken from the back of the pelvis. Local anesthesia or sedation can be used depending on the situation and the patient's age or condition.
  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 17, 2026. · Read our editorial policy