Lymphoma is a cancer that begins in the lymphatic system, a key part of the body’s immune network. This system includes organs like the lymph nodes, spleen, and bone marrow, which transport infection-fighting white blood cells. Lymphomas are broadly categorized into Hodgkin lymphoma and non-Hodgkin lymphoma (NHL). Within NHL, doctors classify them by “grade,” reflecting how quickly cancer cells grow and spread. This grading guides management strategies.
Defining Low Grade Lymphoma
Low-grade lymphoma, also known as indolent lymphoma, refers to a group of non-Hodgkin lymphomas characterized by their slow growth and less aggressive nature. These lymphomas often progress over many years, allowing individuals to live with the condition for extended periods, sometimes without immediate need for treatment. Unlike aggressive lymphomas that grow quickly and require prompt intervention, low-grade types are considered slow-moving. This slow progression means they may not cause significant symptoms when initially diagnosed. Low-grade lymphomas are typically of B-cell origin, meaning they develop from abnormal B lymphocytes, a type of white blood cell. They account for about 40% of all NHL diagnoses in North America and Northern Europe. Common types include Follicular Lymphoma (most prevalent), Chronic Lymphocytic Leukemia (CLL) and Small Lymphocytic Lymphoma (SLL), and Marginal Zone Lymphoma, which can occur in lymph nodes, outside lymph nodes (extranodal), or in the spleen.
Common Symptoms
Many individuals with low-grade lymphoma may not experience any noticeable symptoms, with the condition often discovered incidentally during routine medical examinations or tests for unrelated issues. When symptoms do occur, they can be vague and non-specific. The most common physical sign is swollen, painless lymph nodes, typically found in the neck, armpit, or groin.
Other potential symptoms, sometimes referred to as “B symptoms,” include unexplained fever, drenching night sweats, and unintended weight loss. While these B symptoms are significant for prognosis, other general symptoms like persistent fatigue, loss of appetite, or itching do not hold the same importance. An enlarged spleen or liver can also occur, potentially leading to a feeling of fullness.
How Low Grade Lymphoma is Diagnosed
Diagnosing low-grade lymphoma begins with a thorough medical history and physical examination, where a doctor will check for swollen lymph nodes and assess other potential areas of involvement. The definitive method for confirming a diagnosis and determining its specific type and grade is a biopsy. An excisional biopsy, which involves removing an entire lymph node, is considered the most reliable method as it provides a sufficient tissue sample for detailed laboratory analysis. Pathologists examine the cells under a microscope to identify cancerous cells and classify the lymphoma subtype.
Beyond the biopsy, several other diagnostic tools are used to understand the extent of the disease, a process known as staging. Imaging tests such as CT scans, PET scans, and MRI scans help identify affected lymph nodes or other organs throughout the body. A bone marrow biopsy may be performed to check if lymphoma cells have spread to the bone marrow. Blood tests are important for assessing overall health, organ function, and detecting abnormal levels of certain cells or proteins that can indicate the presence or activity of lymphoma. These tests may include a complete blood count (CBC), erythrocyte sedimentation rate (ESR), and lactate dehydrogenase (LDH) levels.
Treatment Options and Outlook
For many individuals diagnosed with low-grade lymphoma, particularly when they are asymptomatic, immediate treatment may not be necessary. Instead, a common approach is “watch and wait,” also known as active surveillance. This involves close monitoring of the disease without active intervention, as low-grade lymphomas grow slowly and early treatment may not improve overall survival. Treatment is typically initiated if symptoms become bothersome, if there is organ compression, or if the disease shows signs of rapid progression.
When treatment is required, various options are available:
Radiation therapy may be used, especially for localized low-grade lymphomas, and can sometimes lead to long-term control or even cure in early stages.
Chemotherapy, which uses medications to destroy cancer cells, is another option, often combined with other therapies.
Targeted therapies, such as monoclonal antibodies, specifically attack certain proteins on cancer cells and are frequently used for B-cell lymphomas.
Immunotherapy aims to enhance the body’s own immune system to fight the cancer.
In some cases, a stem cell transplant might be considered.
The prognosis for low-grade lymphomas is generally favorable, with many patients living for many years, even decades, with the disease. While a complete cure is not always achieved, especially for widespread disease, the slow-growing nature often allows for effective management and prolonged survival. Some low-grade lymphomas can, however, transform into more aggressive forms over time, which necessitates ongoing monitoring. This chronic nature means individuals often experience periods of remission and may require multiple courses of treatment throughout their lives.