Lymphoma is a type of cancer that begins in infection-fighting cells of the immune system, called lymphocytes. These cells are part of the lymphatic system, which includes the lymph nodes, spleen, thymus gland, and bone marrow. Lymphocytes are found throughout the body, so lymphoma can start almost anywhere. When lymphoma develops, lymphocytes grow out of control, forming tumors that can crowd out healthy cells and impair the body’s ability to fight infection. There are two main types of lymphoma: Hodgkin lymphoma and non-Hodgkin lymphoma, each with distinct characteristics and treatment approaches.
Causes:
The exact cause of lymphoma is often unknown, but certain risk factors have been identified. Lymphoma occurs when a lymphocyte develops a genetic mutation, causing it to grow and multiply uncontrollably, forming a tumor.
- Weakened Immune System:
- Organ transplant recipients taking immunosuppressant drugs.
- Individuals with HIV/AIDS.
- Those with inherited immune deficiencies.
- Infections:
- Epstein-Barr Virus (EBV): Linked to some types of Hodgkin lymphoma and non-Hodgkin lymphoma (e.g., Burkitt lymphoma).
- Helicobacter pylori (H. pylori): Associated with some types of gastric lymphoma (MALT lymphoma).
- Human T-cell Leukemia/Lymphoma Virus type 1 (HTLV-1): Can cause adult T-cell leukemia/lymphoma.
- Hepatitis C Virus (HCV): Linked to some types of non-Hodgkin lymphoma.
- Exposure to Certain Chemicals and Toxins:
- Some pesticides, herbicides, and solvents (e.g., benzene) have been implicated, though the link is not always conclusive.
- Age:
- Hodgkin lymphoma is most common in early adulthood (15-35 years) and late adulthood (over 55).
- Non-Hodgkin lymphoma risk generally increases with age.
- Family History: Having a close relative with lymphoma may slightly increase risk.
- Autoimmune Diseases: Conditions like rheumatoid arthritis, Sjögren’s syndrome, and celiac disease are associated with a higher risk of certain lymphomas.
- Radiation Exposure: High-dose radiation exposure (e.g., from atomic bomb survivors or previous cancer treatment) increases risk.
- Obesity: Some studies suggest a link between obesity and an increased risk of certain non-Hodgkin lymphomas.
Symptoms:
Symptoms of lymphoma can vary depending on the type, location, and stage of the cancer. They often include swollen lymph nodes, but can also involve systemic symptoms.
- Swollen Lymph Nodes: Painless swelling of lymph nodes in the neck, armpit, or groin is a common symptom.
- Fever: Unexplained, persistent, or recurrent fever.
- Night Sweats: Drenching night sweats.
- Weight Loss: Unexplained weight loss (often more than 10% of body weight over six months).
- Fatigue: Persistent and overwhelming tiredness.
- Itching: Generalized itching without a rash.
- Pain: Pain in lymph nodes after drinking alcohol (more specific to Hodgkin lymphoma, but rare).
- Coughing or Shortness of Breath: If lymphoma affects lymph nodes in the chest.
- Abdominal Pain or Swelling: If lymphoma affects the spleen, liver, or abdominal lymph nodes.
- Skin Rashes or Lesions: In some rare types of lymphoma affecting the skin.
Diagnosis:
Diagnosing lymphoma typically involves a combination of physical examination, biopsy, and imaging tests to determine the type and extent of the disease.
- Physical Examination: The doctor will check for swollen lymph nodes in the neck, armpits, and groin, and may check the spleen and liver for enlargement.
- Lymph Node Biopsy: The definitive diagnostic test. A surgeon removes an entire lymph node (excisional biopsy) or a part of it, which is then examined under a microscope by a pathologist to identify lymphoma cells and determine the specific type.
- Bone Marrow Biopsy and Aspiration: To check if lymphoma has spread to the bone marrow.
- Imaging Tests:
- CT Scan (Computed Tomography): To locate enlarged lymph nodes or tumors in the chest, abdomen, or pelvis.
- PET Scan (Positron Emission Tomography): Often combined with CT (PET/CT) to detect areas of increased metabolic activity, indicating cancer cells, and to assess the extent of the disease.
- MRI (Magnetic Resonance Imaging): May be used to examine specific areas, such as the brain or spinal cord.
- Blood Tests: To check blood cell counts, kidney and liver function, and levels of certain proteins (e.g., LDH) that can be elevated in lymphoma.
- Lumbar Puncture (Spinal Tap): If there is concern that lymphoma may have spread to the central nervous system, a sample of cerebrospinal fluid (CSF) is collected.
Treatment:
Treatment for lymphoma depends on the type of lymphoma (Hodgkin or non-Hodgkin), its specific subtype, stage, the patient’s age, overall health, and symptoms. Treatment aims to destroy cancer cells and achieve remission.
- Chemotherapy: Uses drugs to kill cancer cells throughout the body. Can be given intravenously, orally, or by injection. Often given in cycles.
- Radiation Therapy: Uses high-energy rays to kill cancer cells in a specific area. Often used for localized lymphoma or to treat symptoms.
- Immunotherapy: Uses the body’s own immune system to fight cancer.
- Monoclonal Antibodies: Target specific proteins on lymphoma cells (e.g., Rituximab for CD20-positive lymphomas).
- Immune Checkpoint Inhibitors: Block proteins that prevent immune cells from attacking cancer (e.g., Nivolumab, Pembrolizumab).
- Targeted Therapy: Drugs that specifically target vulnerabilities in cancer cells, often with fewer side effects than traditional chemotherapy.
- Stem Cell Transplantation (Bone Marrow Transplant): Used for some patients with aggressive or relapsed lymphoma. High-dose chemotherapy or radiation is given to destroy cancer cells, followed by infusion of healthy blood-forming stem cells (autologous or allogeneic).
- CAR T-cell Therapy: A type of immunotherapy where a patient’s own T-cells are genetically modified in a lab to better recognize and kill cancer cells, then infused back into the patient. Used for certain types of aggressive non-Hodgkin lymphoma that have relapsed or are refractory to other treatments.
- Watchful Waiting (Active Surveillance): For some slow-growing (indolent) non-Hodgkin lymphomas that are not causing symptoms, treatment may be delayed until the disease progresses or symptoms appear.
Patients with lymphoma are often treated by a team of specialists, including hematologist-oncologists, radiation oncologists, and pathologists. Regular follow-up is crucial to monitor for remission, recurrence, and side effects of treatment.
