Lymphoma

What lymphoma is

The lymphatic system includes lymph nodes, the spleen, thymus, bone marrow and lymphoid tissue in the gut, tonsils and skin. Lymphocytes, the main cells of this system, come in two main types, B cells and T cells. Lymphoma happens when lymphocytes acquire genetic changes that make them grow uncontrollably. Because lymphocytes circulate, lymphoma can appear in almost any part of the body.

Hodgkin vs non-Hodgkin lymphoma

Common non-Hodgkin subtypes

• diffuse large B-cell lymphoma (DLBCL): the most common; fast-growing (aggressive) but often curable
• follicular lymphoma: slow-growing (indolent); often managed for many years
• marginal zone lymphoma, including MALT lymphoma of the stomach linked to H. pylori
• mantle cell lymphoma
• Burkitt lymphoma: very fast-growing, more common in children
• chronic lymphocytic leukemia / small lymphocytic lymphoma: the same disease in blood or nodes
• T-cell lymphomas, including cutaneous T-cell lymphoma in the skin

Symptoms

• painless swollen lymph nodes in the neck, armpit or groin, often rubbery and slowly growing. Most swollen lymph nodes are due to infection, but nodes that persist for weeks without explanation should be checked
• B symptoms: unexplained fever above 38 °C (100.4 °F), drenching night sweats, and loss of more than 10% of body weight in 6 months
• itching all over the body, especially in Hodgkin lymphoma
• fatigue
• chest symptoms: cough, breathlessness or chest pressure from enlarged nodes in the chest
• abdominal symptoms: fullness, pain or swelling from an enlarged spleen or abdominal nodes
• in Hodgkin lymphoma, occasionally pain in the nodes after drinking alcohol

Risk factors

• age (most non-Hodgkin lymphomas)
• weakened immune system: HIV, organ transplant medicines
• autoimmune diseases: Sjögren's syndrome, rheumatoid arthritis, lupus, celiac disease
• infections: Epstein-Barr virus, H. pylori, hepatitis C, HTLV-1, HIV
• family history
• previous chemotherapy or radiation
• some chemicals, such as certain pesticides and solvents

Most people with lymphoma have none of these risk factors.

Diagnosis

1. Examination of all lymph node areas, the spleen and liver.
2. Lymph node biopsy: removing a whole node (excisional) or a core of tissue is the key test. Fine-needle aspiration alone is usually not enough. Pathologists use special stains and genetic tests to identify the exact subtype.
3. PET-CT scan: shows where the lymphoma is in the body and how active it is; used for staging and to judge treatment response.
4. Blood tests: blood counts, LDH, liver and kidney function, HIV and hepatitis B and C tests.
5. Bone marrow biopsy for some subtypes.

Staging

Lymphoma is staged I to IV (Lugano classification): stage I is one node area, stage II two or more areas on the same side of the diaphragm, stage III areas on both sides, and stage IV spread to organs such as bone marrow, liver or lungs. Treatment also depends on subtype, symptoms and risk scores.

Treatment

Treatment is tailored to the subtype, stage and the person's health:

• watchful waiting for slow-growing lymphomas without symptoms, which may not need treatment for years
• chemotherapy, often combined with immunotherapy. For example, R-CHOP or newer combinations for DLBCL, and ABVD or similar regimens for Hodgkin lymphoma
• monoclonal antibodies such as rituximab, which target B cells
• radiation therapy for localized disease or in combination with chemotherapy
• targeted drugs such as BTK inhibitors for some B-cell lymphomas
• immune checkpoint inhibitors and brentuximab vedotin for some Hodgkin lymphomas
• CAR T-cell therapy: the patient's own T cells are engineered to attack lymphoma, used for relapsed or refractory disease
• bispecific antibodies for relapsed lymphomas
• stem cell transplant for some relapsed lymphomas
• H. pylori eradication for early gastric MALT lymphoma, which can cure it

Outlook

Hodgkin lymphoma has high cure rates, with 5-year survival of nearly 90% overall in the US. Non-Hodgkin lymphoma outcomes vary: many aggressive lymphomas are curable, while indolent lymphomas often behave like chronic conditions that can be controlled for many years. Survivors need follow-up for relapse and late effects of treatment, such as heart problems and second cancers.

Frequently asked questions

What are the early signs of lymphoma?

The most common early sign is a painless, persistent swelling of lymph nodes in the neck, armpit or groin. Other signs include fevers, drenching night sweats, unexplained weight loss, itching, fatigue, cough or breathlessness.

What is the difference between Hodgkin and non-Hodgkin lymphoma?

Hodgkin lymphoma contains distinctive Reed-Sternberg cells, often affects young adults, spreads predictably and is highly curable. Non-Hodgkin lymphoma is a larger group of many subtypes, more common in older adults, with outcomes that vary by subtype.

Is lymphoma curable?

Many lymphomas are. Hodgkin lymphoma and many aggressive non-Hodgkin lymphomas such as DLBCL are often cured. Slow-growing lymphomas are usually not cured but can be controlled for many years with treatment as needed.

Are swollen lymph nodes a sign of lymphoma?

Usually not. Most swollen nodes are caused by infections and shrink within a few weeks. A node that is painless, rubbery, larger than about 1 inch, growing, or present for more than 4 weeks, especially with fevers or sweats, should be checked.