Understanding Your Medical Test: What It Is, How It Is Done, and Why Your Doctor Ordered It
This test uses fluorescent probes to detect specific chromosome abnormalities in B-cell lymphoma tissue samples.
{"FISH testing analyzes chromosomes in lymphoma cells to identify genetic abnormalities","Helps doctors diagnose lymphoma type and predict prognosis","Guides treatment decisions by identifying specific genetic targets","Requires a tissue sample obtained through biopsy","Results help determine if targeted therapies may be effective"}
Key facts at a glance
- LOINC
- 101787-0
- Short code
- BCL-FISH
- Synonyms
- B-cell lymphoma chromosome al Tiss FISH
- Category
- chemistry
- Sample
- serum
- Container
- Sterile container with RPMI 1640 or saline for fresh tissue; 10% neutral buffered formalin for paraffin-embedded tissue
- Units
- N/A
- Ref low
- 7
- Ref high
- 56
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- Fluorescence In Situ Hybridization (FISH)
- CPT
- 88377
- SNOMED
- 413980006
- Specimen volume
- Fresh tissue: 1 cm³ minimum (approximately 5x5x5 mm); paraffin block or 4-5 unstained slides (4-5 μm thick) plus 1 H&E slide
- Stability
- Fresh tissue: 24 hours at 2-8°C; formalin-fixed paraffin-embedded (FFPE) tissue: indefinite at room temperature; fixed cell suspensions: up to 72 hours at 2-8°C
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 48–168 hours
- Order
- routine
This test is a diagnostic procedure that helps your healthcare provider evaluate your health by measuring specific substances, cells, or functions in your body. Your doctor uses the results to screen for health conditions, confirm or rule out a diagnosis, or monitor how well a current treatment is working over time.
B-cell lymphoma chromosome analysis by FISH (Fluorescence In Situ Hybridization) is a specialized laboratory test that examines genetic material in lymphoma cells. FISH uses fluorescent probes that attach to specific chromosomes or genes, allowing doctors to detect abnormalities like gene rearrangements, amplifications, or deletions that are common in B-cell lymphomas.
The way this test is performed depends on the type of sample or measurement your doctor needs. Most tests involve giving a small sample of blood, urine, or tissue, or using imaging equipment. A trained nurse or technician will walk you through each step, and the procedure is usually quick, safe, and only mildly uncomfortable if at all.
A tissue sample is obtained through a biopsy (usually from a lymph node or tumor). In the laboratory, the tissue is processed and special fluorescent probes are applied to the cells. These probes bind to specific genetic sequences. Under a fluorescence microscope, the technician can see whether the expected genetic patterns are normal or abnormal. The test looks for specific chromosomal changes commonly seen in B-cell lymphomas, such as translocations involving MYC, BCL2, BCL6, and other genes.
Your doctor may order this test to find the cause of symptoms you are experiencing, to screen for a disease before symptoms appear, to check how well a specific organ is working, or to track your response to treatment. The results give your care team important information they need to make informed decisions about your ongoing health and care plan.
Your doctor may order this test to: (1) Confirm a diagnosis of B-cell lymphoma, (2) Determine the specific subtype of lymphoma, (3) Assess prognosis (outlook), (4) Identify genetic abnormalities that may respond to targeted therapies, and (5) Monitor disease progression or recurrence.
Reference range
Adult males: 7-56 U/L; Adult females: 7-43 U/LN/A
No special patient preparation required. Tissue specimen should be collected via surgical biopsy, excisional biopsy, or core needle biopsy under sterile conditions. Coordinate with pathology for fresh or fixed tissue submission.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
FISH testing provides crucial information for managing B-cell lymphomas. Specific genetic abnormalities detected by FISH can classify lymphoma subtypes (such as diffuse large B-cell lymphoma, follicular lymphoma, or Burkitt lymphoma), which guides treatment selection. For example, detecting MYC gene rearrangement may indicate a more aggressive lymphoma requiring intensive treatment. FISH results also help identify patients who may benefit from targeted therapies like rituximab or other agents that work against specific genetic markers.
Frequently asked questions
How long does it take to get results?
Do I need to fast before this test?
What do abnormal results mean?
Is this test painful?
Will this test determine my treatment plan?
Sources
- 1
- 2
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