Lymphoma refers to a group of blood cancers that develop in the lymphatic system. The lymphatic system is part of the immune system and helps fight infection and disease. There are two main types of lymphoma: Hodgkin lymphoma and non-Hodgkin lymphoma. Lymphoma develops when white blood cells called lymphocytes grow abnormally and multiply uncontrollably. When lymphocytes cluster together in the lymph nodes, spleen, or other lymphatic tissue, they can form solid masses called tumors. However, not all lymphomas form solid masses. The presentation of lymphoma depends on the type and where it develops in the body.
Lymphoma Tumor Types
There are a few key differences between Hodgkin lymphoma and non-Hodgkin lymphoma:
Hodgkin Lymphoma
– Named after Dr. Thomas Hodgkin, who first described the disease in 1832
– Accounts for about 10% of all lymphomas
– Characterized by the presence of Reed-Sternberg cells
– Often starts in lymph nodes in the neck or chest
– Tends to be very responsive to radiation therapy
Non-Hodgkin Lymphoma
– Encompasses all lymphomas that do not contain Reed-Sternberg cells
– Accounts for about 90% of all lymphomas
– Can start anywhere lymphatic tissue is found
– Includes over 60 subtypes, most common are diffuse large B-cell and follicular lymphoma
– Treatment depends on the subtype but can include chemo, radiation, immunotherapy
So in summary, Hodgkin lymphoma is more likely to present as solid tumor masses in lymph nodes, while non-Hodgkin lymphoma is a broader group that may or may not form solid masses depending on the subtype.
How Lymphoma Forms Tumors
Lymphoma starts when a lymphocyte acquires DNA mutations that allow it to divide uncontrollably. The abnormal lymphocytes crowd out healthy cells in the bone marrow and lymph nodes, forming solid tumor masses.
In Hodgkin lymphoma, the Reed-Sternberg cells clump together and accumulate in lymph nodes, most often in the neck or chest areas. This causes the lymph nodes to painlessly swell over time. A telltale sign of Hodgkin lymphoma is the presence of swollen lymph nodes without infection or illness.
Non-Hodgkin lymphomas are more diverse, but many subtypes also lead to solid lymph node enlargement. However, some non-Hodgkin lymphomas involve tissues outside the lymph nodes and do not form solid masses. For example, leukemic non-Hodgkin lymphoma spreads abnormal cells through the bloodstream.
Signs and Symptoms
The signs and symptoms of lymphoma depend on where the disease is located in the body. Common symptoms include:
– Swollen, painless lymph nodes in the neck, armpits or groin
– Unexplained fatigue
– Unintentional weight loss
– Drenching night sweats
– Fever
– Itchy skin
Lymph nodes enlarged by lymphoma often present as round, rubbery, movable masses under the skin. They are usually not tender or painful. The swollen nodes are often what prompt medical evaluation and lymphoma diagnosis.
Testing and Diagnosis
If lymphoma is suspected based on clinical exam, imaging tests and biopsy are needed to confirm the diagnosis and classify the subtype.
Imaging Tests
– Chest X-ray: Can detect swollen lymph nodes in chest.
– CT scan: Provides 3D images that show size and shape of lymph nodes and tumors.
– PET scan: Used to map lymphoma in the body and evaluate if it is still active after treatment.
– MRI: Provides detailed images of soft tissues and lymph nodes.
Biopsy
A lymph node biopsy is needed to diagnose lymphoma under the microscope and test for certain cell markers. This is typically an excisional biopsy, meaning the entire abnormal lymph node is surgically removed for analysis. Bone marrow biopsy may also be done to check for lymphoma in the bone marrow.
Subtyping
Once a lymphoma diagnosis is confirmed, further tests are conducted to determine the exact subtype, such as:
– Immunophenotyping: Identifies proteins on the lymphoma cells
– Cytogenetics: Analyzes chromosomes of lymphoma cells
– Fluorescence in situ hybridization (FISH): Detects gene changes in cells
Correct subtyping is key for selecting the appropriate treatments for the individual patient.
Is Lymphoma Considered a Solid Tumor?
Lymphoma is generally categorized as a solid tumor malignancy when it presents as an enlarged lymph node or mass in the body. However, some forms of non-Hodgkin lymphoma primarily involve the blood and bone marrow rather than forming solid masses.
According to the National Cancer Institute:
– Hodgkin lymphoma is considered a solid tumor disease.
– Diffuse large B-cell lymphoma, follicular lymphoma, and other non-Hodgkin lymphomas that form solid tumor masses are classified as solid tumors.
– Leukemic non-Hodgkin lymphomas that mainly affect the blood and bone marrow are called “liquid tumors.”
So in summary, whether lymphoma is considered a solid or liquid tumor depends on the specific subtype and where the cancer cells are located. Solid lymphomas can be felt as lumps under the skin and seen on imaging scans. Liquid lymphomas spread through the blood and can be hard to detect.
Staging Lymphoma
Once diagnosed, lymphoma needs to be staged to determine the extent of the disease in the body. Staging provides key information for prognosis and guides treatment decisions.
Lymphoma is staged from I to IV based on the location of cancer cells:
| Stage I | Cancer is found in one lymph node region or lymphatic site (early disease) |
| Stage II | Cancer is in two or more lymph node regions on the same side of the diaphragm |
| Stage III | Cancer is in lymph node areas on both sides of the diaphragm |
| Stage IV | Cancer has spread outside the lymphatic system to other organs (advanced disease) |
Imaging tests like CT, PET, and MRI scans give information about the locations affected to determine lymphoma stage. Bone marrow biopsy is also important for staging. Stage I and II are considered early stage while Stage III and IV are advanced.
Outlook and Survival Rates
Lymphoma is highly treatable in many cases, especially when diagnosed at an early stage. Treatment may eliminate lymphoma entirely or keep it well-controlled for many years.
The 5-year survival rate tells the percentage of people who live at least 5 years after diagnosis. The American Cancer Society reports the following average 5-year survival rates:
– Hodgkin lymphoma: 85%
– Non-Hodgkin lymphoma: 69%
However, survival rates can vary significantly based on specific patient factors like age, subtype, stage, and response to treatment.
Some key factors affecting lymphoma prognosis include:
– Age: Younger patients often have better outcomes.
– Stage: Early stage has higher survival rates.
– Subtype: Some lymphoma types are more aggressive.
– Overall health: Good health and strength improve tolerance to treatments.
– Treatment response: Patients who respond well to initial therapy tend to do better.
So in general, lymphoma patients who are younger, healthier, diagnosed early, and respond well to treatment can expect very favorable outcomes, sometimes living decades past diagnosis.
Conclusion
In summary, whether lymphoma presents as a solid mass depends on the specific subtype. Hodgkin lymphoma and many non-Hodgkin lymphomas form observable tumors in lymph nodes and other tissues. However, leukemic non-Hodgkin lymphomas do not form solid masses and primarily affect the blood and bone marrow. Lymphomas that present as solid masses are categorized as solid tumors, while leukemic lymphomas are called liquid tumors. Staging determines how far the lymphoma has spread and guides treatment. With modern treatments, lymphoma prognosis can be quite good, particularly when diagnosed at an early stage. Being aware of the signs and symptoms of lymphoma is important for getting prompt evaluation and treatment.