Follicular lymphoma is a type of non-Hodgkin lymphoma that develops from B lymphocytes, which are white blood cells involved in the body’s immune response. It is generally considered an indolent, or slow-growing, lymphoma. However, its behaviour can vary, and some cases may develop more aggressive features.
For Nigerians experiencing persistent swollen lymph nodes, unexplained weight loss, or other concerning symptoms, understanding lymphoma and its diagnostic process can help them seek appropriate medical attention.
Modern laboratory testing, including fluorescence in situ hybridization (FISH), can provide important genetic information about lymphoma cells. Two relevant diagnostic pathways are the IGH/BCL2 t(14;18) FISH test associated with follicular lymphoma and broader FISH testing used in the investigation of aggressive lymphomas.
Follicular Lymphoma:
Follicular lymphoma is a cancer of B lymphocytes that usually grows slowly and often begins in lymph nodes. It belongs to the group of non-Hodgkin lymphomas.
The disease may affect lymph nodes in the neck, armpits, groin, or abdomen. In some patients, it may also involve the spleen or bone marrow.
Because follicular lymphoma can develop gradually, some people may have few symptoms at first. Others may notice painless swelling of lymph nodes or experience general symptoms such as tiredness, fever, or unexplained weight loss.
Follicular Lymphoma in Nigeria: Why Awareness Matters
Lymphoma can affect people of different ages and backgrounds, including individuals living in Nigeria. However, the available Nigerian cancer registry data do not provide enough evidence to establish a reliable national prevalence specifically for follicular lymphoma.
Non-Hodgkin lymphoma has been reported in Nigerian cancer registry studies, but cancer registration has historically faced challenges involving completeness, geographical coverage, and diagnostic documentation.This makes awareness of lymphoma symptoms and access to appropriate diagnostic evaluation important.
Factors that may complicate lymphoma diagnosis
Several practical challenges may affect the diagnosis of lymphoma in Nigeria:
- Overlapping symptoms: Swollen lymph nodes may result from infections, inflammatory conditions, or cancer. Symptoms alone cannot establish a lymphoma diagnosis.
- Differences in healthcare access: Access to specialist haematology, oncology, pathology, and advanced laboratory services may vary between locations.
- Complex disease classification: Different lymphomas can appear similar clinically but require different diagnostic approaches.
- Need for tissue-based diagnosis: Proper classification often depends on examining a biopsy and performing additional laboratory tests.
These challenges are reasons to encourage appropriate medical evaluation rather than assume that a symptom has a particular cause.
Symptoms of Follicular Lymphoma
Follicular lymphoma may develop without obvious symptoms. When symptoms occur, they can vary depending on which lymph nodes or organs are affected.
1. Painless swollen lymph nodes
A common sign is a gradually enlarging, painless lymph node in the:
- Neck
- Armpit
- Groin
- Chest or abdomen
Not every enlarged lymph node indicates lymphoma. Infections and other conditions can cause similar swelling. A persistent or enlarging lump should be assessed by a healthcare professional.
2. Unexplained weight loss
Losing weight without deliberately changing diet or exercise habits can be a warning sign of several medical conditions, including some lymphomas.
Unexplained weight loss is particularly important when it occurs alongside persistent lymph-node swelling or other systemic symptoms.
3. Fever and night sweats
Some people with lymphoma experience fever without an obvious cause or drenching night sweats.
These symptoms are sometimes called B symptoms when they occur in the context of lymphoma. They can also arise from infections and other illnesses, so they require clinical assessment rather than self-diagnosis.
4. Persistent tiredness
Fatigue may occur in lymphoma and can be associated with the disease itself, anaemia, inflammation, or other health problems.
Persistent tiredness should be evaluated, especially when accompanied by other unexplained symptoms.
5. Abdominal discomfort or early fullness
If lymphoma affects lymph nodes or organs in the abdomen, a person may experience abdominal discomfort, a feeling of fullness after eating small amounts, or other digestive symptoms.
These symptoms have many possible causes and should be interpreted by a doctor.
When Should Nigerians Seek Medical Evaluation?
A person should seek medical advice if they notice a lymph node that:
- Persists or continues to enlarge.
- Is not explained by a recent infection.
- Is accompanied by unexplained fever, night sweats, or weight loss.
- Occurs with unusual fatigue or other concerning symptoms.
How Is Follicular Lymphoma Diagnosed?
Diagnosing follicular lymphoma usually involves several complementary investigations. No single blood test or genetic test can reliably diagnose every case of lymphoma.
1. Medical history and physical examination
A doctor may ask about:
- The duration and progression of symptoms.
- Recent infections or illnesses.
- Unexplained weight changes.
- Fever and night sweats.
- Previous medical conditions.
- The location and size of swollen lymph nodes.
The examination may include checking lymph nodes and assessing the spleen or other areas that could be affected.
2. Lymph-node or tissue biopsy
A biopsy involves removing a sample of tissue for examination by a pathologist.
For suspected follicular lymphoma, tissue architecture is often important because the arrangement of cells within a lymph node can help distinguish different lymphoma types.
Depending on the clinical situation, the doctor may recommend an excisional biopsy, an incisional biopsy, or another suitable tissue-sampling method.
3. Histopathology
Histopathology involves examining tissue under a microscope.
The pathologist assesses the appearance and arrangement of cells and may identify features that suggest a particular type of lymphoma.
4. Immunohistochemistry and immunophenotyping
These laboratory techniques examine proteins or markers associated with specific cell types.
They can help determine whether abnormal cells are B lymphocytes and assist in distinguishing follicular lymphoma from other lymphoid malignancies.
5. Imaging and staging investigations
Depending on the clinical findings, doctors may request imaging studies such as CT or PET-CT scans to assess the distribution of disease.
Blood tests, including a complete blood count and other investigations, may also be used to evaluate overall health and identify findings relevant to diagnosis and treatment planning.
6. Genetic and molecular testing
Genetic tests can identify specific changes in lymphoma cells.
FISH is one method used to investigate chromosome rearrangements. The results may provide additional information that helps a specialist classify a lymphoma alongside pathology and immunophenotyping.
What Is FISH Testing?
FISH stands for fluorescence in situ hybridization.
It is a laboratory technique that uses specially designed fluorescent DNA probes to identify specific genes or chromosome regions in cells or tissue.
In simple terms, FISH helps laboratory specialists look for a particular genetic rearrangement.
How does FISH work?
- A suitable cell or tissue sample is prepared in the laboratory.
- Fluorescently labelled DNA probes are applied to the sample.
- The probes attach to their matching genetic regions.
- A specialist examines the fluorescent signals using a microscope.
- The signal pattern is interpreted and reported according to the laboratory’s validated testing method.
FISH is useful because it can detect selected genetic rearrangements even when those changes are not readily identified through routine microscopy alone.
Understanding the IGH/BCL2 t(14;18) FISH Test
The IGH/BCL2 t(14;18) FISH test is designed to investigate a rearrangement involving the IGH and BCL2 gene regions.
The notation t(14;18) refers to a translocation involving chromosome 14 and chromosome 18. In the commonly associated rearrangement, the immunoglobulin heavy-chain region on chromosome 14 becomes linked to the BCL2 region on chromosome 18.
Common genetic targets in aggressive B-cell lymphoma investigations
In the evaluation of certain large B-cell lymphomas, FISH testing may investigate rearrangements involving:
- MYC: A gene involved in cell growth and proliferation.
- BCL2: A gene involved in regulating cell survival.
- BCL6: A gene important in the development and function of germinal-centre B cells.
Some aggressive B-cell lymphoma classifications depend on identifying particular combinations of genetic rearrangements. For example, the investigation of high-grade B-cell lymphoma may require assessment of MYC and, when appropriate, BCL2 and BCL6.
The exact composition of the DNA Labs Nigeria aggressive lymphoma panel should be confirmed from the laboratory’s current test specification.
Can FISH Testing Be Positive Without Follicular Lymphoma?
Yes. The IGH/BCL2 rearrangement is strongly associated with follicular lymphoma, but it is not exclusive to that diagnosis.
A genetic rearrangement may also be identified in other B-cell lymphoid conditions. In addition, the detection of a rearrangement alone does not establish that a person has clinically significant lymphoma.
This is why the FISH result must be reviewed with the tissue diagnosis and other laboratory findings.
A specialist may also request additional genetic tests when the morphology or immunophenotype suggests a different type of lymphoma.
Frequently Asked Questions
1. What is follicular lymphoma?
Follicular lymphoma is a type of B-cell non-Hodgkin lymphoma that usually grows slowly. It commonly affects lymph nodes and may involve other parts of the lymphatic system.
2. What does t(14;18) mean?
The notation t(14;18) describes a chromosome translocation involving chromosomes 14 and 18. In follicular lymphoma, it commonly involves the IGH and BCL2 gene regions.
3. Why is IGH/BCL2 FISH testing used?
It is used to investigate the IGH/BCL2 rearrangement, which is strongly associated with classic follicular lymphoma. The result may support lymphoma classification when interpreted alongside pathology and other tests.
4. Does a positive IGH/BCL2 FISH result confirm follicular lymphoma?
No. A positive result alone does not confirm a complete lymphoma diagnosis. A pathologist and treating specialist must interpret it with tissue morphology, immunophenotyping, and the clinical findings.
5. Can follicular lymphoma occur in Nigerians?
Yes. Nigerians can develop follicular lymphoma, as can people from other populations. However, reliable national data on the exact prevalence of follicular lymphoma in Nigeria are limited.
6. Is every swollen lymph node a sign of lymphoma?
– Infections, inflammation, and other conditions can cause enlarged lymph nodes. Persistent, enlarging, or unexplained swelling should be assessed by a healthcare professional.
7. What is the difference between follicular lymphoma and aggressive lymphoma?
Follicular lymphoma is usually slow-growing, whereas aggressive lymphomas may progress more rapidly. The distinction requires proper clinical and laboratory evaluation.
8. What is an aggressive lymphoma FISH panel used for?
It is used to investigate selected genetic rearrangements relevant to aggressive lymphomas. The specific targets depend on the laboratory’s panel and the suspected disease.
9. Can FISH testing replace a biopsy?
Usually, no. FISH provides targeted genetic information, while a biopsy often supplies essential information about tissue architecture and cell morphology. Both may be needed for accurate lymphoma classification.
10. Who should interpret a lymphoma FISH result?
A qualified pathologist, haematologist, oncologist, or other appropriately trained healthcare professional should interpret the result in the context of the complete clinical and laboratory assessment.
Conclusion
Follicular lymphoma is a form of non-Hodgkin lymphoma that can develop gradually and may initially cause few symptoms. Persistent swollen lymph nodes, unexplained weight loss, fever, night sweats, or ongoing fatigue should be assessed by a healthcare professional.
Accurate diagnosis often involves biopsy, histopathology, immunohistochemistry, imaging, and selected genetic investigations.
The IGH/BCL2 t(14;18) FISH test can help investigate a rearrangement associated with follicular lymphoma. Broader FISH testing may be relevant when aggressive B-cell lymphoma is suspected.
For Nigerian patients and families, understanding the purpose and limitations of these tests can support informed discussions with healthcare professionals and encourage appropriate diagnostic evaluation.
Explore lymphoma genetic testing
To learn more about the relevant laboratory investigations, visit the following DNA Labs Nigeria test pages:
