Lymphoma is a type of cancer that originates in the lymphatic system, a part of the body’s immune system. This network includes lymph nodes, spleen, thymus, and bone marrow, all working to fight infections and diseases. Low-grade lymphoma is a form of cancer, affecting lymphocytes that grow and multiply abnormally. The designation “low grade” refers to the slow growth rate and less aggressive behavior of these cancer cells, distinguishing them from more rapidly progressing types.
What “Low Grade” Means for Lymphoma
The term “low grade” in lymphoma, often referred to as indolent, indicates that the cancer cells divide slowly and behave less aggressively compared to high-grade lymphomas. Despite this slower progression, low-grade lymphoma remains a malignant condition that necessitates medical attention. Under a microscope, the cells of low-grade lymphomas often appear more similar to normal cells, described as well-differentiated. This cellular appearance reflects their slower proliferation rate.
However, it is still a cancer with the capacity to spread throughout the lymphatic system and, in some cases, to other parts of the body. While it may not always require immediate aggressive treatment, its presence disrupts the normal functioning of the immune system. Some low-grade lymphomas also have the potential to transform into higher-grade, more aggressive forms over time, requiring ongoing monitoring. This transformation can occur due to further genetic changes within the cancer cells.
Common Forms of Low-Grade Lymphoma
Several types of lymphoma are classified as low grade. Follicular lymphoma is the most common low-grade non-Hodgkin lymphoma (NHL). This type originates from B-cells within lymph nodes and can affect areas like lymph nodes, bone marrow, and the spleen. Its slow growth means symptoms may develop gradually or be absent initially.
Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL) are considered different manifestations of the same disease. Both involve abnormal B-cells; CLL primarily affects the blood and bone marrow, while SLL mainly involves the lymph nodes. Marginal Zone Lymphoma (MZL) is another low-grade B-cell lymphoma that can arise outside the lymph nodes (extranodal, like MALT lymphoma in the stomach), in the lymph nodes (nodal), or in the spleen (splenic).
How Low-Grade Lymphoma is Diagnosed and Monitored
Diagnosing low-grade lymphoma begins with a physical examination and an evaluation of symptoms, like painless swollen lymph nodes. A definitive diagnosis relies on a biopsy, where a tissue sample, often from an enlarged lymph node, is removed for microscopic examination. An excisional or incisional biopsy, which removes an entire lymph node or a significant portion, is often preferred for accurate classification. While bone marrow biopsies may be performed to check for disease spread, they are not the primary diagnostic tool for initial confirmation.
In addition to biopsies, imaging scans like CT and PET scans determine the extent of the lymphoma and staging. Blood tests, like complete blood counts and liver and kidney function tests, assess overall health, though they do not definitively diagnose lymphoma. Immunophenotyping, a specialized test, helps identify specific proteins on cancer cells, crucial for classifying the lymphoma type. For many individuals with low-grade lymphoma, especially if asymptomatic, “watchful waiting” or “active surveillance” is employed. This involves regular check-ups and monitoring without immediate active treatment.
Managing Low-Grade Lymphoma and What to Expect
When active intervention becomes necessary for low-grade lymphoma, various treatment approaches are available, tailored to the type, stage, and symptoms. Common treatments include chemotherapy, often combined with immunotherapy drugs like rituximab, which target proteins on cancer cells. Radiation therapy may be used for localized disease, while targeted therapies focus on molecular pathways involved in cancer growth. Treatment decisions are carefully considered based on the patient’s condition.
For many, low-grade lymphoma is considered a chronic condition that can be managed over an extended period, often with long remissions between treatments. While a complete cure is not always the primary goal, controlling the disease and maintaining a good quality of life are central to management. Individuals with low-grade lymphoma often live long lives, even with the presence of the disease. However, it is possible for the lymphoma to recur, requiring further rounds of treatment. In some instances, low-grade lymphoma can undergo a transformation into a more aggressive form, necessitating more intensive therapeutic interventions.