What does the lymphatic system contain?
The lymphatic system is a main component of the immune system. They contain various lymph organs, lymph nodes and vessels.
Lymph: it is a clear fluid which contains lymphocytes ( B cells, and T cells)
Lymph nodes: it is an aggregate of lymphoid tissues which is usually pea-sized and cannot be felt over the skin unless infected. They are scattered in various regions like the neck, armpit, groin, chest and abdomen.
Lymphatic organs: they are vital parts to the whole lymphatic system. They are the spleen, thymus, tonsils etc.
Since lymphatic tissue is present everywhere, the lymphoma can start anywhere.
Non-Hodgkin’s lymphoma most commonly involves the T cells.
What is non – Hodgkin’s lymphoma?
Non – Hodgkin’s lymphoma is a type of cancer of the lymphatic system. It affects the lymphocytes which are a part of the white blood cells. This type of lymphoma is more common amongst the two types. Non-Hodgkin’s lymphoma has over 60 subtypes which all have slight variations in morphology.
What causes Non-Hodgkin’s lymphoma?
- Epstein Barr virus: is known to cause Burkitt Lymphoma
- Helicobacter pylori: is associated with gastric lymphoma
- HHV -8: a type of virus that is associated with primary effusion lymphoma
- Hepatitis C virus: splenic marginal zone lymphoma, lymphoplasmacytic lymphoma, diffuse large B-cell lymphoma
- HIV infections
- Chemical substances like polychlorinated bi-phenyls, diphenylhydantoin and phenoxy herbicide.
- Radiation and chemotherapy
- Genetic diseases: Chediak- Higashi syndrome, Klinefelter syndrome, ataxia-telangiectasia syndrome
- Autoimmune diseases: Sjogren syndrome, celiac disease, rheumatoid arthritis, systemic lupus erythematosus
- Genetic history: although not as common as Hodgkin’s lymphoma, it is observed to cause NHL.
What are the types of Non-Hodgkin’s Lymphoma?
Since there are many morphologic variations of Non-Hodgkin’s lymphomas, the classification is also elaborate. The grouping of the different types is based on the following factors:
- The type of lymphocyte it begins from (B cell or T cell)
- How it looks under the microscope
- How the chromosome varies under microscope
- The presence of certain proteins on the surface of the cells
BASED ON THE LYMPHOCYTE IT BEGINS FROM:
- Diffuse large B-cell lymphoma: this is the most common type of B cell lymphoma. It is seen in people over the age of 60. The cancer is fast-growing and is seen beginning from both superficial and deep lymph nodes. It responds well to treatment and medications. Most patients are completely cured of the lymphoma post treatment. Primary mediastinal B-cell Lymphoma is a subtype which is seen in women more commonly. It occurs at the chest region and shows rapid enlargement. It may even impinge on the trachea and cause difficulty in breathing.
- Follicular lymphoma: it is a form of lymphoma which again occurs in older individuals. It is slow-growing and respond well to treatment. They may not be treated completely in go. They need not be treated unless the lymphoma causes any problems. It may later transform into diffuse large B cell lymphoma.
- Small lymphocytic lymphoma: doctors consider this type to be another version of chronic lymphocytic leukaemia. It is slow-growing and the cancer cells are found in the lymph nodes and spleen. They have the same treatment modality as chronic lymphocytic leukaemia. They are usually not curable with standard treatments but patients can live a long time with them. Sometimes, they turn into an aggressive form.
- Mantle cell lymphoma: about 5%of the cases are mantle cell lymphomas. They seem to affect men more frequently than women. They have a tendency to grow rapidly and not respond well to the conventional treatments. The newer line of treatments offer a better prognosis.
- Marginal zone lymphoma: they are types of lymphomas that make up about 5-10% of all the lymphomas. They are a slow growing type of lymphoma there are three types of marginal zone lymphoma:
- Mucosa associated lymphoid tissue lymphoma (MALT): in this type of lymphoma, the origin is from non-lymphatic regions. They may originate from the stomach, skin, lung, thyroid, salivary gland etc and spread to the lymphatic tissues. MALT is linked to bacterial infections.
- Nodal marginal zone B-cell lymphoma: this type of lymphoma is more common in women. They start and usually stay in the lymph nodes. They may occasionally spread to the bone marrow. They are slow growing and have a better prognosis.
- Splenic marginal zone lymphoma: this is a slow growing lymphoma which is usually confined to the spleen and bone marrow. It is linked to be associated with hepatitis C virus. The patient may experience pain and discomfort due to the enlargement of the spleen. The lymphoma does not require treatment until the symptoms turn painful and pose as hindrance.
- Burkitt lymphoma: the lymphoma is named after the discoverer and is more commonly seen in males. It is a rare form contributing to about 1-2% of the total cases. It is more common in children than adults. The tumour is fast growing and requires immediate intensive radiation therapy. There are two sub types:
- The African variety: this is linked to the association of Epstein Barr virus. It commonly affects the jaw and the facial bones.
- The non-African variety: this is seen more commonly in the United States. It begins in the abdomen, ovary, or testicles and spread to the brain and spinal cord. They are not associated with Epstein Barr virus.
- Lymphoplasmacytic lymphoma (Waldenstrom macroglobinaemia): this is a very rare type of lymphoma which is seen in the bone marrow, lymph nodes and spleen.
- Hairy cell leukaemia: despite the name, many believe that it is a type of lymphoma. It is more common in men over the age of 50. Small B cell lymphocytes with projections are a characteristic feature giving the “hairy cell appearance”. They are seen in the spleen and bone marrow. this lymphoma responds to treatment well and usually is asymptomatic.
- Primary central nervous system lymphoma: this is a very rare type of lymphoma which affects the brain, spinal cord and sometimes the eyes. It is more common in older patients, especially those who have had organ transplants or AIDS. The patient presents with blurred vision, altered sensations, weakness or sometime seizures. The prognosis is considerably poor compared to the other lymphomas but they do respond to therapy.
- Precursor T-lymphoblastic lymphoma: this type accounts for 1% of the lymphomas it can be considered as a form of acute lymphoblastic leukaemia depending on the involvement of the bone marrow. this lymphoma starts in the thymus (an organ that is present behind the breastbone and in front of the heart). This can lead to its swelling which may obstruct breathing. This type is more common in the young adults. It presents a good prognosis if it is detected before it spreads to the bone marrow.
- Peripheral T cell lymphoma: these are some of the uncommon types which develop from the mature form of T cells.
- Cutaneous T cell lymphoma: they begin from the skin
- Adult T-cell lymphoma: they are a rare form that is caused by infections from a virus called HTLV-1. It affects the bone marrow, lymph nodes, spleen, liver, skin, and other organs.
- Angioimmunoblastic T cell lymphoma: it is more common in adults. It tends to affect the lymph nodes, spleen or liver which tend to get enlarged. Affected individuals present with fever, weight loss and skin rashes. The treatment is quick and effective but it tends to recur.
- Extranodal natural killer/ T cell lymphoma, nasal type: this type involves the airway passages and may also invade the skin, digestive system, and other organs.
- Enteropathy associated intestinal T-cell lymphoma: this is a type of lymphoma that involves the lining of the intestine, more commonly, the small intestine. Patients present with severe abdominal pain, nausea and vomiting.
- Anaplastic large cell lymphoma: this type is rare and fast growing which is more common in young adults.
- Peripheral T-cell lymphoma, not otherwise specified: this is the name given to the group for those which do not fit into any other type of lymphoma. They affect the lymph nodes and spread to the spleen, skin, bone marrow, liver, and digestive tract. They are fast growing and are difficult to treat.
What are the symptoms of non-Hodgkin’s lymphoma?
- Painless swollen lymph nodes of the armpit and groin.
- Abdominal pain and swelling
- Chest pain
- Cough and trouble in breathing
- Night sweats and chills
- Unexplained weight loss.
- Itching of the skin
How is non-Hodgkin’s lymphoma detected?
The detection is similar to that of Hodgkin’s lymphoma.
Pay attention to symptoms like enlargement of one or more lymph nodes. It may be accompanied with fever, night sweats, weight loss, tiredness, and abdominal swelling. Report to the doctor with the symptoms for screening tests. Early detection increases the survival rate drastically and can even be life-saving.
- Biopsy: biopsy is the only way to confirm a non-Hodgkin’s Lymphoma. The different biopsies that can be done are:
- Excisional biopsies: the entire lymph node is removed and is sent for biopsy.
- Incisional biopsy: a small section of the tissues are removed from the swelling and is sent for biopsy.
- Needle biopsy: a needle bore is inserted into the swelling and the fluid is drawn into the barrel. It is then sent for cytology. It is of two types: fine needle aspiration cytology and core needle biopsy.
- Bone marrow aspiration biopsy: it is the needle biopsy done to aspirate contents from the bone marrow and then sent for biopsy.
- Lumbar puncture: this is done to aspirate the cerebrospinal fluid from the lumbar region. It is useful in cases where the lymphoma is spread to the CSF.
- Lab tests:
- Flow cytometry and immunohistochemistry
- Chromosome tests
- Imaging tests like X rays, C T scans, MRI, ultrasound, PET scans and bone scans.
- Blood tests:
- Complete blood count
- Blood chemistry
- Lactate dehydrogenase levels
- Hepatitis B, hepatitis C and HIV tests.
- Heart and lung tests:
- Pulmonary function test
What are the available treatment modalities for NHL?
There are various treatment modalities available. It can be classified based on the approaches:
- Treatment of B-cell non-Hodgkin’s lymphoma
- Treatment of T-cell non-Hodgkin’s lymphoma
- Treatment of HIV associated lymphoma
The stage of cancer is determined and the treatment is then carried out.
The treatments available are:
- Targeted therapy
- Radiation therapy
- Stem cell transplant
- Surgery (not preferred)
- Palliative support in extreme cases.