Lymphoma

Lymphoma is a hematologic solid tumor that develops in the lymphatic system.

The lymphatic system is a network of vessels, nodes and organs that maintains fluid balance and produces WBCs (White Blood Cells) or lymphocytes to fight against infections.

A lymphoma is considered a cancer of the lymphatic system. It produces an uncontrolled growth of different types of cells, mainly some types of lymphocytes. Lymphocytes are a type of WBCs (White Blood Cells) that actively fight infections.

There are two main types of lymphocytes:

• T lymphocytes: They are more common among adults.
• B lymphocytes: They are more common in children.

Lymph nodes are small pea-shaped organs found along the network of lymph vessels. Their main function is to make and store lymphocytes.

Clusters of lymph nodes are found in the pelvis region, underarm, neck, chest, and abdomen. The spleen, the thymus and the tonsils are also part of the lymphatic system.

A lymphoma may start in almost any organ of the body because there is lymph tissue in many parts of the body. The organs most frequently involved are the lymph nodes, the spleen, the bone marrow and the liver.

Lymphomas can be divided into two main types:

• Hodgkin's lymphoma or Hodgkin's disease: They account for about 10% of all cases. They are usually located only in one area of the body and has a predictable pattern of spread to the other lymph nodes. They do not usually affect mesenteric nodes or the Waldeyer ring. They usually have a better prognosis.
• Non-Hodgkin's lymphomas: They are the most common type (90% of the cases). They usually affect peripheral lymph nodes and do not exhibit the contiguous spreading pattern of the Hodgkin's lymphomas. They can spread to almost any other part of the body beyond the lymph nodes. They commonly affect mesenteric nodes or the Waldeyer ring.

The main difference between these two groups is the type of lymphocytes that are affected.

To discern between both types of lymphomas, it is necessary to examine the cancer cells under the microscope. Hodgkin's lymphoma is marked by the presence of Reed-Sternberg cells, whereas in non-Hodgkin's lymphoma, these cells are not present.

People with a lymphoma usually visit the doctor when they notice swelling of the lymph nodes in the neck, armpits or groin.

However, the symptoms of lymphomas are often vague and non-specific and may be similar to other diseases. Some common symptoms are:

• Loss of appetite
• Weight loss
• Nausea
• Vomiting
• Abdominal discomfort
• Feeling of fullness (as a result of enlarged lymph nodes in the abdomen)
• Pain in the lower back

In advanced stages, the patient may have the following symptoms:

• Bone pain
• Headache
• Constant coughing
• Congestion in the face, neck and upper chest
• Fever
• Night sweat

It is often difficult to diagnose lymphomas because there are no specific screening test available.

A biopsy of the enlarged lymph node is the most definitive diagnostic tool for staging purposes when there is an enlargement of the lymph nodes, liver, or spleen.

In addition, to determine the extent of spread of the disease, conventional imaging tests, such as X rays, computed tomography scans (CT scans) or magnetic resonance imaging are available.

Another procedure usually used is called lymphangiograms to get X rays from the lymphatic system. In this procedure, a special dye (usually blue) is injected into the lymphatic channels through a small cut made in each foot for one or several hours. This dye clearly outlines the lymphatic system and allows it to stand out. Multiple X rays are then taken and any abnormality, if present, is revealed.

The appropriate treatment for lymphomas depends on the type of lymphoma and its present stage.

In most cases, the treatment consists of:

• Chemotherapy
• Radiotherapy
• A combination of the two methods

Sometimes, bone marrow transplantation is a possibility. A new experimental treatment for patients with lymphoma known as peripheral stem cell transplantation may be considered.