Sometimes the lymph nodes are not easily found on physical examination. They could be present in the chest or in the abdomen and the only way to detect them is by taking x-rays.

There are two major kinds of lymphomas: Hodgkin's disease and non-Hodgkin's lymphomas. Hodgkin's occurs in the young and is usually associated with a good prognosis, while non-Hodgkin's lymphomas may occur at any age and are associated with a less favorable prognosis. The non-Hodgkin's lymphomas are a very heterogenous group of diseases with a diverse pathology and natural history. They are divided into three major categories: the low grade, intermediate grade, and high-grade lymphomas. In addition, there is a group of lymphomas which could not be categorized in these three groups and may be considered as "special lymphomas."

Frequently Asked Questions

17. What are lymphomas?

1. Lymphomas constitute a spectrum of cancer diseases which afflict the lymphoctye cell and its precursor cells, the main cellular component of the immune system of the human body.

17. What is the cause of lymphoma?

1. There is no established cause for lymphomas. However, it is believed that they develop as the result of hereditary and genetic factors on one side and environmental factors on the other. Most patients have underlying genetic defects. Among environmental factors, the most important is infection. Thus lymphomas may be the product of the combination of infections and genetic defects.

17. Are they curable?

1. Lymphomas are potentially curable diseases and modern medicine may cure up to 80% of all patients with Hodgkin's disease and 60% of all patients with non-Hodgkin's lymphomas.

Risk Factors
There is currently no established cause for lymphomas. However, it is believed that they develop as the result of hereditary and genetic factors on one side and environmental factors on the other. Most patients have underlying genetic defects. Among environmental factors, the most important is infection. Thus, lymphomas may be the product of the combination of infections and genetic defects.

Symptoms
The most common symptoms are low-grade fever, drenching night sweats, generalized itching, and weight loss. Patients may present with one or more of these symptoms and sometimes no symptoms at all.

Physical Findings
These diseases most frequently start as enlarged lymph nodes in the neck, axillae or inguinal regions. These nodes may or may not be associated with symptoms. Sometimes the lymph nodes are not easily found on physical examination. They could be present in the chest or in the abdomen and the only way to detect them is by taking x-rays.

Diagnosis
The ideal way to make a definitive diagnosis is to surgically excise a whole lymph node and submit it for pathological examination. When this is not possible, a fine needle aspiration of the lymph node may confirm the diagnosis. A definitive diagnosis cannot possibly be made short of a pathological examination. Medical evaluation alone is not sufficient for making a diagnosis.

Staging
Staging means the anatomic or geographical mapping of the disease in the body. It addresses the question of how advanced is the disease. The higher the stage, the more advanced is the disease. The process of staging allows the treating physician to determine the precise strategy of treatment, prognosis, and outcome of treatment.

Usually, Stage I means the disease is localized to a lymph node or a group of lymph nodes. Stage II is when the disease is confined to two distinctly different geographical regions of lymph nodes on one side of the body (above or below the diaphragm. The diaphragm separates the abdomen from the chest). Stage III is when the disease exists in the lymph nodes, above and below the diaphragm, and Stage IV is when the disease has already gone outside the lymph nodes to visceral organs like liver, bones, lungs, and bone marrow.

The anatomic stage of the disease is not the only factor that determines the outcome of treatment. Other factors include presence or absence of symptoms, the amount or volume of tumor burden, and the severity of the malignant nature of the lymphoma itself.

Treatment
These diseases are usually treated with chemotherapy and radiation. Surgery has a minimal role in treatment and its major role is confined to diagnosis and staging.

• Radiation Therapy: Radiation therapy alone is a form of treatment which is frequently used for early Hodgkin's disease. In non-Hodgkin's lymphomas, the role of this approach to therapy is limited, and most patients with these diseases require systemic chemotherapy. There is a great deal of controversy as to the different ways of combining radiation and chemotherapy. Most patients need this combination. However, Stage I of Hodgkin's disease may be treated by radiation therapy alone. This may also hold true for non-Hodgkin's lymphoma with Stage I and no symptoms. In all other categories of diseases, systemic chemotherapy becomes indicated.
• Chemotherapy: In Hodgkin's lymphomas, two types of combination chemotherapy are currently used:
  1. MOPP chemotherapy (Mustargen, Oncovin, Procarbazine and Prednisone
  2. ABVD (Adriamycin, Bleomycin, Vinblastine and Dacarbazine)

  The latter is preferred to the former because it is at least as effective but less toxic.

  In non-Hodgkin's lymphoma, the combination chemotherapy known as CHOP (Cyclophosphamide, Adriamycin, Oncovin and Prednisone) is the most commonly employed chemotherapeutic regimen. When patients fail to respond to CHOP, an alternative regimen will be ASHAP (Doxorubicin, Methylprednisolone, high dose Cytarabine Cisplatin).

  Usually 6-9 cycles of chemotherapy are needed to achieve a good control of the disease, but only 20%-30% of these patients will not need further treatment. A large number of patients will eventually relapse (i.e., the disease recurs) and will need additional treatment.

  Treatment is usually associated with side effects including hair loss, nausea, vomiting, marked decrease in the number of white blood cells which predisposes patients to infection and significant decrease in the number of platelets which predisposes patients to bleeding and also fatigue. However, most recently, new drugs and strategies have emerged that significantly minimize these side effects.

• Bone Marrow Transplantation: Different forms of bone marrow transplantation and peripheral stem cell support are being currently evaluated. Although the preliminary finds are suggestive that this approach is useful, its exact role in the strategy of therapy for these diseases remains to be determined.

Prognosis
Prognosis (outcome or what is expected) depends on the following factors:

1. Staging of the disease and how early therapy was started.
2. The exact nature of the lymphoma and how malignant it is.
3. Adequacy of therapy and response to treatment.

Lymphomas are potentially curable diseases and modern medicine may cure up to 80% of all patients with Hodgkin's disease and 60% of all patients with non-Hodgkin's lymphomas.

Research
Research is focusing on the nature and causation of lymphomas. The molecular basis of these diseases is being explored. New approaches in therapy, including the use of biological agents, are being explored. Currently, the use of anti-CD20 monoclonal antibody, Rituxan, has been shown to be effective in low-grade lymphomas. Several experimental agents are in the pipeline for clinical trials.

Last Updated: January 30, 2001
Source: Philip A. Salem, M.D.
Texas Cancer Institute^®