What is Hodgkin's lymphoma?

From the diary ...

Hodgkin's lymphoma (HL) - Hodgkin's diseases is a malignant cell infiltration of the lymphatic system. The malignant cells clone or reproduce themselves so that in time the disease produces a partial or complete destruction of the normally healthy lymph tissue. As a result the lymph nodes become enlarged. The progression of the disease from its original site is due to lymph from the bodies' tissues circulating throughout the lymphatic system. The disease was first described by Thomas Hodgkin in 1832.

Hodgkin's Disease can present at any age. The age related incidence commonly occurs bimodally, with one peak young adults (20-30) and another after the age of fifty. Childhood Hodgkin's is rare. The male: female ratio is about 2:1. Nodular sclerosing is seen more often in young females. There may also be a genetic link to Hodgkin's, as there have been many reported incidences of family members of the same or different generation suffering from HD. To date the complete reasons as to why some people develop it and others don't remains largely unknown.

HL, like other cancers, are diseases of the body's cells. Cells in different parts of the body may work in different ways but all repair and reproduce themselves in the same way. Normally, this division of cells takes place in an orderly and controlled manner but if, for some reason, this process gets out of control the cells will continue to divide, developing into a lump or tumor.

     The lymphatic system is one of the body's natural defences against infection. It is a complex system made up of  lymph organs, such as bone marrow, the thymus and the spleen, and lymph nodes which are connected by a network of tiny lymphatic vessels. Lymph nodes are found mainly in the neck, armpit and groin.

The malignant cells are thought to derive from dendritic reticulum cells, HD is identified almost exclusively by the presence of the large and binucleated Reed - Sternberg cells.

HD can be further sub classified in to four types. Classification can only be determined by histological examination, usually following a biopsy of the affected node. The type and the extent of the progression of disease, will then determine the prognosis and treatment plan; for instance those people that have Lymphocyte Predominance HD at stage 1a will have a higher remission rate than those people who have Lymphocyte Depletion at stage 4 b. Although, one must bear in mind that with so many medical advances it is fair to say that all types have a favourable prognosis. Statistically, over the past twenty years, the cure rate for HD has improved more than any cancer other than testicular cancer.

1- LYMPHOCYTE PREDOMINANCE

The histological appearance is largely of small cell lymphocyte proliferation, with only a few eosinophils, Reed - Sternberg cells and mononuclear Hodgkin's cells.

2- NODULAR SCLEROSING

This is the most common type. The histology shows the lymph node to be divided by broad bands of collagen or connective tissue, these bands encircle nodules containing a mixture of Reed - Sternburg cells, mononuclear Hodgkin cells, lymphocytes, plasma cells,, macrophages and eosinophills.

3- MIXED CELLULARITY

The lymph node is diffusely infiltrated with Reed - Sternburg cells, mononuclear Hodgkin cells, lymphocytes, plasma cells, macrophages and eosinphills. Fibrosis and focal necrosis are readily seen.

4- LYMPHOCYTE DEPLETION

There is either a reticular pattern, with a dominance of Reed - Sternburg cells, or a diffuse fibrosis where the lymph node is replaced by a disordered connective tissue, containing a few lymphocytes. Reed - Sternburg cells may also be infrequent.

The selection of the appropriate treatment depends on accurate staging of the extent of the disease. Your disease will be staged clinically, pathologically or both.
The clinical stage is determined by history, physical examination, x-rays, blood tests and your initial biopsy results.
The pathological stage is if involvement is found at laparotomy or by any further removal of tissue for histological examination other than that taken for the original diagnosis. Both clinical and pathological staging classification apply only to the time of disease presentation and prior to definitive therapy. However, pathological staging may be done during a course of treatment when symptoms demand that treatment to the upper half of the body must be given first, such as in mediastinal compression.
In most institutions the Ann Arbor staging model is used.

Stage I
Involvement of a single lymph node region (I) or of a single extra lymphatic organ or site (Ie).

Stage II
Involvement of two or more lymph node regions on the same side of the diaphragm (II) or localised involvement of extra lymphatic organ or site and of 1 or more lymph node regions on the same side of the diaphragm (Iie).

Stage III
Involvement of lymph node regions on both sides of the diaphragm (III) which may also be accompanied by localised involvement of extra lymphatic organ or site (IIIe) or by involvement of the spleen (IIIs) or both (IIIs e)

Stage IV
Diffuse or disseminated involvement of one or more extra lymphatic organs or tissues with or without associated lymph node enlargement. The reason for classifying at stage IV is identified further by defining sites by symbols.

N - Lymph nodes, S - Spleen, H - Liver, L - Lung, M - Marrow, O - Bone, P - Pleura, D - Skin

The systemic symptoms are further subdivided into A and B categories, B for those with defined general symptoms and A for those without.
The B classification is given to those people who have displayed:

(I) unexplained weight loss of more than 10% of the body weight in the six months before admission.
(II) unexplained fevers with temperatures above 38 st.C.
(III) night sweats.

Pruritis alone does not qualify for B classification.

• Radiotherapy

• Chemotherapy

• Bone marrow transplantation (or peripheral blood stem cells transplantation)

Specific treatment depends on many factors including the type, and stage of lymphoma and the history and condition of the patient. Oncologists take these into account before recommending a treatment protocol.

Radiation therapy uses high-energy x-rays to kill cancer cells and shrink tumors. Radiation for Hodgkin's disease usually comes from a machine outside the body. It can be limited to a mantle field (such as the neck, chest or lymph nodes under the arm) or involve total nodal irradiation.

Chemotherapy uses drugs to kill cancer cells and shrink tumors. Chemotherapy can be taken by pill, or it may be taken intravenously. It is called a systemic treatment because the drugs enter the bloodstream and travel throughout the body. There are many different chemotherapy regimens used to fight lymphoma. Typical treatments for Hodgkin's include MOPP or ABVD or a combination of these drugs. Quite a few regimens exist for NHL, highly dependent on disease type.

Bone marrow (or stem cell) transplantation may be employed when the disease is resistant to other therapies. Because high doses of chemotherapy can destroy healthy bone marrow, the marrow can be replenished by 1) marrow removed from the body before treatment, frozen, then transfused back to the patient after chemotherapy (autologous transplants), or 2) marrow from a matched brother or sister or a marrow match from an unrelated donor (allogenic transplants).

Bone marrow is found inside the bones, particularly the pelvic bones. It is the `factory' for the blood, responsible for producing white blood cells (to protect against infection), red blood cells (to carry oxygen round the body) and platelets (to prevent bleeding).

Stem cells are blood cells at their very earliest stage of development in the bone marrow, before they have become committed to developing into white cells, red cells or platelets. It is these cells which are the key factor in transplants, whether just the stem cells are transplanted or the bone marrow itself (which naturally includes many stem cells).

... more about stem cells transplantation

In the United States, about 7,400 new cases of Hodgkin's disease are expected this year (2000), with about 3,200 occurring in women and 4,200 occurring in men, according to the American Cancer Society (ACS).

The ACS lists lymphomas and leukemia together. In 1999, lymphomas and leukemia were the fifth most common type of cancer and the fourth leading cause of death by type of cancer.

About 1,400 people per year die from Hodgkin's disease in the United States, divided equally among males and females. However, death rates from Hodgkin's disease have fallen more than 60 percent since the early 1970s as more advances in treatment are made. More than 75 percent of people with Hodgkin's disease can be cured with radiation and/or chemotherapy.

The one-year survival rate after treatment is 93 percent. After five years, it is 82 percent, and after 10 years, it is 72 percent, according to the ACS. At 15 years, the overall survival rate is 63 percent. The most common cause of death in patients during the first 15 years after treatment is recurrent Hodgkin's disease. After 15 years, death is more likely due to other causes, such as a secondary type of cancer.