Lymphoma

What is lymphoma?

Lymphoma is a cancer that begins in lymphocytes, a type of white blood cell that helps the body fight infection. Lymphocytes travel through the lymphatic system, a network of thin vessels, lymph nodes (small bean-shaped glands), the spleen, the thymus, the bone marrow, and lymph tissue in the gut and other organs. When lymphocytes develop genetic changes that make them grow out of control and live longer than they should, they can build up in lymph nodes and other tissues and form tumors. That is what doctors mean when they answer the question, what is lymphoma.

There are two main groups of lymphoma. Hodgkin lymphoma is defined by the presence of a specific abnormal cell, called a Reed-Sternberg cell, seen under the microscope. Non-Hodgkin lymphoma is a much larger and more varied group that includes dozens of subtypes. Some of these grow slowly over years (often called indolent or low-grade lymphoma), while others grow quickly over weeks or months (aggressive or high-grade lymphoma). The subtype matters a great deal, because it shapes both the outlook and the treatment plan.

Lymphoma can affect people of any age. Hodgkin lymphoma is somewhat unusual among cancers because it is relatively common in young adults, with a second peak in older age. Most non-Hodgkin lymphomas become more common as people get older, although some subtypes occur in children and young people. Lymphoma is one of the more common cancers in children and teenagers, and it is among the most common blood cancers in adults overall.

Lymphoma symptoms

Lymphoma symptoms can be vague, and many of them overlap with common infections and other conditions. This is one reason the diagnosis is sometimes delayed. The most recognized sign is a swollen lymph node that does not go away, but not everyone with lymphoma notices a lump, and many people with a swollen node do not have cancer.

• Painless swelling of one or more lymph nodes, most often in the neck, armpit, or groin
• Fever that comes and goes without a clear infection
• Night sweats heavy enough to soak clothing or bedding
• Unexplained weight loss, often described as losing about a tenth of body weight over six months without trying
• Persistent tiredness that does not improve with rest
• Itching over large areas of the skin without a rash
• Loss of appetite or feeling full quickly, which can happen when the spleen is enlarged
• Cough, chest pressure, or shortness of breath when nodes in the chest are enlarged
• Abdominal pain or swelling when nodes in the belly, the spleen, or the bowel are involved
• Frequent infections or easy bruising, which may reflect bone marrow involvement

Doctors group fever, drenching night sweats, and unexplained weight loss together as “B symptoms.” Their presence or absence is recorded as part of staging, because B symptoms are associated with more active disease. Some people with Hodgkin lymphoma report pain in an affected lymph node after drinking alcohol; this is uncommon but characteristic when it occurs.

Symptoms often differ by type. Slow-growing non-Hodgkin lymphomas may cause few or no symptoms for a long time and are sometimes found incidentally on a scan done for another reason. Fast-growing lymphomas tend to cause nodes that enlarge quickly and general symptoms that appear over weeks. Lymphomas that start outside the lymph nodes, for example in the stomach, skin, or brain, produce symptoms related to that organ, such as indigestion, skin patches or plaques, or headaches and neurological changes. In later stages, when the bone marrow is affected, low blood counts can lead to anemia (a shortage of red blood cells), infections, and bleeding.

Lymphoma causes and risk factors

In most people, the exact cause of lymphoma is not known. What doctors do understand is that lymphoma develops when a lymphocyte acquires changes in its DNA that switch on growth signals or switch off the normal process that tells damaged cells to die. These changes are usually acquired during life rather than inherited, and they often happen without any identifiable trigger. Discussing lymphoma causes therefore usually means discussing factors that raise risk rather than a single cause.

• Age: risk for most non-Hodgkin lymphomas rises with age, while Hodgkin lymphoma has peaks in young adulthood and later life.
• Weakened immune system: people living with HIV, those taking medicines that suppress immunity after an organ transplant, and people with certain inherited immune disorders have a higher risk.
• Autoimmune diseases: conditions such as rheumatoid arthritis, Sjögren’s syndrome, celiac disease, and lupus are linked to a modestly higher risk of some lymphoma subtypes.
• Infections: Epstein-Barr virus (the virus that causes mononucleosis) is linked to some Hodgkin and non-Hodgkin lymphomas; Helicobacter pylori, a stomach bacterium, is linked to a lymphoma of the stomach lining; hepatitis C and human T-lymphotropic virus type 1 are linked to specific subtypes.
• Family history: having a parent or sibling with lymphoma slightly raises risk, although most people with lymphoma have no affected relatives.
• Chemical and radiation exposure: some pesticides, solvents, and previous radiation therapy or chemotherapy for another cancer are associated with increased risk.
• Sex: most lymphoma types are somewhat more common in men than in women.

It is important to keep these factors in perspective. Most people with one or more risk factors never develop lymphoma, and many people diagnosed with lymphoma have no known risk factor at all. Lymphoma is not contagious and cannot be passed from one person to another.

Lymphoma diagnosis

A swollen lymph node or a set of unexplained symptoms is only the starting point. Because so many conditions can enlarge lymph nodes, doctors usually begin with a medical history and a physical examination, checking the size and feel of nodes in the neck, armpits, and groin and looking for an enlarged spleen or liver. If a node has been enlarged for several weeks without an obvious infection, or if it is unusually large, hard, or growing, further testing is usually recommended.

Lymphoma diagnosis is confirmed by a biopsy, which means removing tissue so it can be examined under a microscope. The most reliable approach is usually an excisional biopsy, in which an entire lymph node is removed, or a core needle biopsy, in which a larger needle takes a cylinder of tissue. A fine needle aspiration, which draws out only a few cells, is often not enough to classify lymphoma properly. A pathologist (a doctor who specializes in examining tissue) looks at the cells and performs additional tests, such as immunohistochemistry and flow cytometry, which identify specific proteins on the cell surface, and genetic tests that look for particular chromosome changes. Together these tests determine the exact subtype, which is essential for planning treatment.

Once lymphoma is confirmed, staging tests show how far it has spread. These commonly include:

• Blood tests, including a complete blood count, kidney and liver function, lactate dehydrogenase (an enzyme that can be raised in active lymphoma), and screening for viruses such as HIV and hepatitis B and C, which can affect treatment choices.
• CT scans of the neck, chest, abdomen, and pelvis to measure enlarged nodes and organs.
• PET-CT scan, which uses a small amount of radioactive sugar to show metabolically active disease; it is now the standard staging test for most lymphoma types and is also used to assess response to treatment.
• Bone marrow biopsy, in which a small sample of marrow is taken from the hip bone; this is still needed for some subtypes, although PET-CT has replaced it in others.
• Lumbar puncture (spinal tap) or MRI of the brain in certain aggressive lymphomas where spread to the nervous system is a concern.
• Heart and lung function tests before starting treatments that can affect these organs.

Lymphoma is staged from I to IV based on how many lymph node regions are involved, whether disease is on one or both sides of the diaphragm (the muscle separating the chest from the abdomen), and whether organs outside the lymphatic system are affected. The letters A or B are added to show whether B symptoms are present. For some subtypes, doctors also calculate a prognostic score that combines stage, age, blood results, and general fitness to help guide treatment decisions.

Lymphoma treatment options

Lymphoma treatment options depend on the subtype, the stage, the speed of growth, the person’s age and general health, and their own preferences. Treatment is usually coordinated by a hematologist or medical oncologist, a doctor who specializes in blood cancers and cancer medicines. In a hospital group such as Acibadem, this care is typically organized through the Medical Oncology Department working alongside pathology, radiology, and radiation oncology teams. The main approaches are outlined below.

Observation (watch and wait). For some slow-growing lymphomas that are causing no symptoms, starting treatment immediately has not been shown to improve outcomes. In these cases the doctor may recommend regular check-ups and scans and begin treatment only when symptoms develop or the disease grows. This can feel counterintuitive, but it spares people the side effects of treatment they may not need for years.

Chemotherapy. Chemotherapy uses medicines that kill rapidly dividing cells. It is given through a vein or by mouth in cycles, usually over several months, and remains a cornerstone of treatment for many lymphomas. Different subtypes use different combinations of drugs. Side effects can include tiredness, nausea, hair loss, a higher risk of infection, and effects on the heart or nerves depending on the drugs used; many of these are manageable and temporary.

Immunotherapy and targeted therapy. Monoclonal antibodies are laboratory-made proteins that attach to a marker on lymphoma cells and help the immune system destroy them; they are often combined with chemotherapy in non-Hodgkin lymphoma. Antibody-drug conjugates deliver chemotherapy directly to the cell. Checkpoint inhibitors release the brakes on the immune system and are used in some Hodgkin lymphomas. Targeted tablets that block specific growth signals inside the cell are used in certain subtypes. Bispecific antibodies and CAR T-cell therapy, in which a person’s own immune cells are modified in a laboratory to recognize lymphoma, are newer options for some lymphomas that have come back or not responded to standard treatment.

Radiation therapy. Radiation uses high-energy beams aimed precisely at affected areas. It may be used alone for early-stage slow-growing lymphoma limited to one region, combined with chemotherapy in Hodgkin lymphoma and some aggressive lymphomas, or to relieve symptoms from a large mass.

Stem cell transplant. For lymphomas that return or resist initial treatment, doctors may recommend high-dose chemotherapy followed by an infusion of blood-forming stem cells to rebuild the bone marrow. The cells may be the person’s own (autologous) or from a donor (allogeneic). This is an intensive treatment and is only suitable for people who are fit enough to tolerate it.

Surgery. Surgery is used mainly to obtain a biopsy. It is rarely a primary treatment for lymphoma, because the disease is usually spread through the lymphatic system, but it may occasionally be used for lymphomas confined to a single organ such as the spleen or part of the bowel.

Supportive care and rehabilitation. Supportive treatments include medicines to prevent nausea and infection, growth factors that help blood counts recover, blood transfusions when needed, and antiviral treatment when infections such as hepatitis are present. After treatment, many people benefit from a gradual return to physical activity, nutrition advice, and psychological support. Fertility preservation is discussed before treatment when relevant, since some therapies can affect the ability to have children.

Living with lymphoma and outlook

The outlook for lymphoma varies widely, and no single statement applies to everyone. Many lymphomas, including most cases of Hodgkin lymphoma and several aggressive non-Hodgkin lymphomas, are treated with the goal of cure, and a large proportion of people treated go on to live long lives without the disease returning. Slow-growing lymphomas are often not curable in the traditional sense but can frequently be controlled for many years, with periods of treatment followed by long periods of good health, so that some people live with them as a long-term condition. Factors that influence outlook include the specific subtype, the stage at diagnosis, age, general health, the results of blood tests such as lactate dehydrogenase, and how well the lymphoma responds to the first treatment.

After treatment, follow-up appointments continue for several years to watch for relapse and for late effects of treatment, which can include heart or lung problems, thyroid changes, and a small increased risk of other cancers. Doctors usually recommend staying up to date with vaccinations (some live vaccines may need to be avoided during and shortly after treatment), not smoking, being physically active, and attending routine screening programs. Many people experience fatigue, anxiety, or difficulty concentrating for months after treatment ends. These effects are common and usually improve gradually; support groups, counseling, and rehabilitation programs can help.

Frequently asked questions

What is lymphoma and how is it different from leukemia?

Both are cancers of white blood cells, but they behave differently. Lymphoma usually forms solid collections of abnormal lymphocytes in lymph nodes or organs, while leukemia mainly involves abnormal cells circulating in the blood and crowding the bone marrow. Some conditions sit on the boundary between the two, and the distinction is made by the pathologist based on where and how the cells are found.

What are the first lymphoma symptoms people usually notice?

The most common first sign is a painless lump in the neck, armpit, or groin that persists for weeks. Others notice unexplained tiredness, fever, drenching night sweats, or weight loss before any lump. Because these symptoms are shared with many minor illnesses, they do not mean a person has lymphoma, but symptoms that persist or worsen over several weeks should be evaluated.

What are the main lymphoma causes, and can it be prevented?

In most cases no specific cause is identified. Known risk factors include a weakened immune system, certain infections, some autoimmune conditions, older age, and family history, but most people with these factors never develop lymphoma. Because the causes are largely unknown or not controllable, there is no proven way to prevent lymphoma, although avoiding HIV infection and treating Helicobacter pylori or hepatitis C when present may lower the risk of specific subtypes.

How is lymphoma diagnosis confirmed?

Only a biopsy can confirm lymphoma. Blood tests and scans can raise suspicion and show where disease may be, but a tissue sample examined by a pathologist, along with laboratory tests that identify markers on the cells, is required to make the diagnosis and determine the exact subtype. Staging scans, most often PET-CT, then show how far the disease has spread.

What lymphoma treatment options are available if the first treatment does not work?

Several options may be considered depending on the subtype and the person’s fitness. These can include a different chemotherapy combination, targeted tablets, antibody-based treatments, high-dose chemotherapy with a stem cell transplant, or CAR T-cell therapy. Your doctor may also discuss clinical trials. The choice depends on how quickly the lymphoma came back and how well earlier treatment was tolerated.

Is lymphoma hereditary?

Most lymphoma is not inherited. Having a close relative with lymphoma slightly increases risk, and rare inherited immune disorders raise risk more substantially, but in the great majority of cases the genetic changes that cause lymphoma are acquired during a person’s lifetime and are not passed on to children.

Can lymphoma come back after treatment?

Yes, lymphoma can return, a situation doctors call relapse. The likelihood varies by subtype: slow-growing lymphomas often recur over time and are managed with repeated courses of treatment, while many aggressive lymphomas and Hodgkin lymphoma that stay in remission for several years are less likely to return. This is why follow-up continues for years after treatment ends.

When to see a doctor

A swollen lymph node that appears during a cold or throat infection usually settles within two to three weeks. It is reasonable to see a doctor if a lymph node stays enlarged for more than a few weeks, keeps growing, feels hard or fixed, or is not accompanied by any sign of infection. The same applies to unexplained fever, night sweats, weight loss, or persistent tiredness lasting more than a few weeks. Seek urgent medical attention if you experience any of the following:

• Difficulty breathing, noisy breathing, or a feeling of pressure in the chest or neck, which can indicate a large mass in the chest
• Swelling of the face, neck, or arms, especially with a bluish tint or bulging veins
• Fever during chemotherapy or any temperature above 38°C (100.4°F) while your immune system is suppressed, since infection can become serious quickly
• Severe or worsening abdominal pain, vomiting, or inability to pass stool, which may signal a blockage
• Sudden confusion, severe headache, weakness on one side, or seizures
• Unusual bleeding or bruising, blood in the urine or stool, or black stools
• New back pain with leg weakness, numbness, or loss of bladder or bowel control, which can indicate pressure on the spinal cord

These warning signs do not always mean lymphoma or a complication of lymphoma, but they need prompt assessment. If you have already been diagnosed with lymphoma, your treatment team will usually give you specific guidance about which symptoms to report immediately and how to reach them out of hours.