The lymphatic system — also called the lymph or lymphoid system — works with the circulatory and immune systems to help protect the body. It is made up of a network of lymph vessels and lymph nodes that carry lymph, a clear fluid derived from blood plasma and containing white blood cells. Those white blood cells (lymphocytes) fight infections and other threats, while lymph nodes act as filters that trap foreign particles.

Lymphoma (lymph cancer) happens when lymphocytes grow and divide uncontrollably. It most often appears in lymph nodes but can start in other parts of the lymphatic system or in extranodal tissues (for example, the spleen, skin, or gastrointestinal tract). A common early sign is painless swelling of a node — for example, in the neck or groin — though symptoms vary depending on where the disease develops.

What is Lymph (Lymphoma) Cancer?

Lymphoma is a cancer of the lymphatic system — a network of lymph vessels and lymph nodes that helps the body fight infections. It is one of the more common hematological cancers and can present with a wide variety of clinical and biological features. Lymphomas typically form concentrated growths in lymph nodes, where lymph vessels meet, but they can also start in other parts of the lymphatic system or in extranodal tissues such as the spleen, skin, gastrointestinal tract, thymus, or bone marrow.

Epidemiology varies by subtype: lymphoma overall is seen more often in men than women, and incidence generally rises with age, though patterns differ between types and regions. For example, some forms are more common in younger adults while others increase in older age groups; frequency also varies by geography and race.

Clinically, we divide lymphomas into two broad categories: Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). Hodgkin lymphoma (named after Thomas Hodgkin) has characteristic Reed–Sternberg cells and includes classic and non-classic forms. Non-Hodgkin lymphoma is a heterogeneous group that arises from different lymphocyte types — mainly B lymphocytes, but also T cells or natural killer cells — and because the lymphatic system runs throughout the body, NHL can appear in many locations. Non-Hodgkin lymphoma accounts for the majority of lymphoma cases, while Hodgkin lymphoma makes up a smaller proportion overall. For more on how doctors classify and stage these cancers, see the Stages and Diagnosis sections below.

What Are the Symptoms of Lymph (Lymphoma) Cancer?

Symptoms of lymphoma depend on where the disease is in the body, but some signs are common across many types. The most frequent early sign is unexplained, usually painless swelling of a lymph node — often in the neck, under the arm, or in the groin. Below are common systemic “red flag” symptoms and organ-specific symptoms to watch for.

Red flags (see a doctor if present):

  • A swollen lymph node or nodes that are new, growing, hard, or persist for more than 3–4 weeks
  • Unexplained fevers or drenching night sweats
  • Rapid, unintentional weight loss or loss of appetite

Other symptoms that may occur when specific organs or systems are involved:

  • Abdominal pain, bloating, indigestion, or vomiting — if lymph nodes or lymphoma affect the gastrointestinal tract or spleen
  • Skin redness, lumps, or nodules — when the skin is involved
  • Persistent cough, chest tightness, or shortness of breath — if lymph nodes in the chest or the respiratory system are affected
  • Headache, vision changes, weakness, or nerve-related symptoms — if the nervous system is involved

Because lymphoma symptoms often overlap with common infections and other conditions, persistent or unexplained signs should prompt medical evaluation. Your doctor will consider the pattern of lymph node enlargement, systemic symptoms (fever, night sweats, weight loss), and relevant tests to determine whether further diagnostic steps are needed.

What Causes Lymph Cancer?

Researchers do not point to a single cause for lymphoma, but we do know that the disease results from genetic changes in lymphocytes that allow those cells to grow and divide without normal control. In many lymphomas, specific mutations or chromosomal translocations (for example, changes affecting genes such as MYC or BCL2 in certain subtypes) drive malignant behavior.

Risk factors that can increase the chance of developing lymphoma fall into several groups:

  • Infectious agents: Some infections are linked to particular lymphoma types — Epstein–Barr virus (EBV) with Burkitt lymphoma and some Hodgkin and non-Hodgkin subtypes, Helicobacter pylori with gastric MALT lymphoma, HTLV-1 with adult T‑cell leukemia/lymphoma, and HIV infection with higher lymphoma risk.
  • Immune system problems: Long-term immune deficiency (either inherited, acquired such as HIV, or caused by immunosuppressive drugs after transplantation) raises lymphoma risk.
  • Genetic and biological factors: A family history or inherited predisposition can contribute, and specific gene abnormalities are central to the disease process.
  • Environmental and health-related factors: Some studies link obesity and exposure to certain medications or chemicals with slightly increased risk; socioeconomic and geographic factors also influence incidence patterns.

If you have known risk factors or persistent symptoms (for example, enlarged lymph nodes, unexplained fevers, night sweats, or weight loss), discuss them with your doctor. They can advise on appropriate testing and monitoring based on your individual history and risk profile.

Stages of Lymph (Lymphoma) Cancer

Staging describes how far lymphoma has spread in the body and helps doctors choose the best treatment. The most commonly used system is the Ann Arbor classification, which relies on imaging such as CT or PET scans and sometimes bone marrow evaluation. Staging indicates whether disease is limited to one area or is systemic and may be combined with prognostic scores (for example, the International Prognostic Index for many non‑Hodgkin lymphomas) to guide therapy.

Ann Arbor stages (basic definitions):

  • Stage I: Involvement of a single lymph node region or a single extralymphatic organ or site.
  • Stage II: Involvement of two or more lymph node regions on the same side of the diaphragm, or a single extralymphatic organ plus its regional lymph nodes on the same side of the diaphragm (often noted as Stage II E).
  • Stage III: Lymph node regions on both sides of the diaphragm are affected; this may include involvement of the spleen or limited extranodal disease.
  • Stage IV: Diffuse or disseminated involvement of one or more extralymphatic organs (for example, bone marrow, liver, or lung) with or without associated lymph node involvement.

Modifiers commonly used with Ann Arbor staging: “A” or “B” indicates absence or presence of systemic symptoms (B symptoms = fever, drenching night sweats, or unexplained weight loss), and “E” denotes limited extranodal extension from a nodal site. Example: Stage II E means nodal disease on one side of the diaphragm with a single adjoining extranodal site. Staging plus prognostic indices help determine whether treatment is intended to be curative or palliative and which specific therapies are recommended.

How is Lymph Cancer Diagnosed?

Diagnosis begins when a patient or doctor notices persistent lymph node enlargement or other worrying symptoms. Because many lymphoma signs mimic common infections, clinicians follow a stepwise approach: clinical evaluation, tissue diagnosis, and then staging and laboratory tests to guide treatment.

Typical diagnostic pathway:

  1. History and physical exam: your doctor assesses the pattern of lymph node enlargement, systemic symptoms (fever, night sweats, weight loss), and any organ-specific signs.
  2. Biopsy for definitive diagnosis: an excisional lymph node biopsy (removal of the whole node) yields the most information about lymphoma subtype; core needle biopsy may be used when excision is not feasible. Pathology will include microscopic examination, immunophenotyping, and genetic tests.
  3. Staging imaging: PET/CT or contrast-enhanced CT scans map disease spread and identify involved lymph nodes and extranodal sites.
  4. Laboratory tests and marrow assessment: baseline blood tests (CBC, chemistry, LDH) help assess organ function and tumor activity; bone marrow biopsy may be recommended for certain subtypes or if marrow involvement is suspected.
  5. Infectious disease screening: before treatment, tests for hepatitis B (HBV), hepatitis C (HCV), and HIV are commonly performed because positive results affect therapy choices and prophylaxis.

Note: blood tests alone are often normal in early lymphoma; elevated lactate dehydrogenase (LDH) can suggest more active disease but is non‑specific. After diagnosis, your care team (usually including a hematologist/oncologist) combines staging results and prognostic scores to plan treatment. If you have a persistent enlarged node or unexplained systemic symptoms, see your doctor — prompt evaluation helps get an accurate diagnosis and early treatment when needed.

How is Lymph Cancer Treated?

Treatment for lymphoma aims to stop uncontrolled growth of malignant lymphocytes and, when possible, cure the disease. The specific plan depends on the lymphoma type, stage, patient age, overall health, and prognostic scores. Below are the main treatment approaches, typical uses, and brief examples.

  • Chemotherapy: Cytotoxic drug regimens remain a cornerstone of treatment for many lymphomas. Combinations are used to increase effectiveness—an example is R‑CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) commonly used for diffuse large B‑cell lymphoma (a common non‑Hodgkin lymphoma).
  • Radiotherapy: External beam radiation is effective for localized disease, such as limited-stage Hodgkin lymphoma or for controlling bulky nodal masses. Radiation is often combined with systemic therapy when needed.
  • Immunotherapy and targeted therapy: These include monoclonal antibodies (e.g., rituximab for many B‑cell lymphomas), immune checkpoint inhibitors (used in some Hodgkin lymphoma cases), antibody–drug conjugates, and CAR‑T cell therapy for certain relapsed or refractory B‑cell non‑Hodgkin lymphomas. Immunotherapy works by harnessing or directing the immune system against cancer cells.
  • Stem cell transplant (hematopoietic cell transplant): Autologous (patient’s own) or allogeneic (donor) stem cell transplants can be used after high‑dose chemotherapy to rescue the bone marrow and offer a chance of long‑term remission in select high‑risk or relapsed cases. Peripheral blood stem cells and bone marrow remain the primary graft sources.
  • Surgery: Surgery is generally limited to diagnostic biopsy or removal of a localized mass in rare cases. It is not a primary treatment for widespread lymphoma.

Treatment goals vary: some lymphomas are treated with curative intent, while others are managed to control symptoms and prolong quality life. Side effects differ by therapy and can include infection risk, fatigue, nausea, fertility effects, and long‑term risks such as secondary cancers; supportive care and survivorship planning are important parts of care.

Examples and clinical notes: R‑CHOP is a standard curative regimen for many aggressive B‑cell non‑Hodgkin lymphomas; radiation alone can cure some early-stage Hodgkin cases; CAR‑T cell therapy has shown benefit in refractory large B‑cell lymphoma. Treatment recommendations follow current guidelines (for example, NCCN, ESMO) and are tailored by a hematologist/oncologist.

If you notice persistent lymph node swelling or systemic symptoms (fever, night sweats, unexplained weight loss) lasting more than 2–4 weeks, schedule a visit with your primary care doctor who can refer you to a hematologist/oncologist for evaluation and, if needed, timely treatment planning.