Hodgkin’s DiseaseHodgkin’s Disease
Cancers arising from the lymph nodes or other sites of lymphoid tissue are broadly termed lymphomas. This group of diseases is divided into Hodgkin’s disease and non-Hodgkin’s lymphoma. In both conditions, there is a replacement of normal lymphatic tissue by collections of abnormal lymphoma cells.
The lymphatic system are a complex network of specialised cells and organs that defend the body against infection. Lymphatic organs include the bone marrow, spleen, thymus gland, lymph nodes, tonsils, adenoids, appendix and clumps of tissue in the small bowel. A function of the lymphatic system is to nurture and mature the B and T-lymphocytes (white blood cells vital to immune function). Cancerous changes can take place when mutation leads to failure of the cells maturing of the lymphoid cells.
Lymphomas are regarded as cancers of lymphocytes. The process which lymphoma occurs consists of a series of events where normal lymphocyte cells cease to mature and develop in an orderly fashion. The genetic make-up of the lymphocyte is altered, resulting in the formation of altered lymph tissue (tumours) or altered lymphocyte secretions. Typically, patients present with a painless swelling of lymph node, with or without fever and night sweats and weight loss.
How Hodgkin’s Is Caused.
The exact cause ofisn’t known. However, different of how it is caused.
The Epstein-Barr virus is a herpes virus that causes infectious mononucleosis (also known as glandular fever). Epstein-Barr virus genes have been identified in tissue samples of approximately 20-50% of individuals with Hodgkin’s disease. However, it is yet to be established whether the Epstein-Barr virus can cause Hodgkin’s disease. The most of people who develop glandular fever will not develop Hodgkin’s disease.
Hodgkin’s disease is associated with a number of rare immune disorders. Chronic inflammatory disorders such as rheumatoid arthritis and systemic lupus erythematous have also been associated with Hodgkin’s disease. Further, the recipients of heart, kidney and other organ transplant have been found to be at an increased risk of developing the illness.
There is some evidence suggesting that first degree relatives of individuals with Hodgkin’s disease is at a small, but increased risk of developing the disease. However, Hodgkin’s disease is not directly heritable. Involved nodes in the neck, groin and armpits tend to be painless, firm, and rubbery. In some instances, the nodes may spontaneously increase and decrease in size.
Because Hodgkin’s disease is associated with a defect in the maturation of the lymphocyte, the immune system may be impaired. As such repeated infections may occur.
The symptoms of Hodgkin’s disease frequently depend upon the stage of disease. Staging defines the extent to which the disease has spread throughout the body. Moreover, it often determines which treatment(s) will be required.
Hodkins has 4 distinct stages of Hodgkin’s disease, these being stages 1-4. Each stage is further defined as exhibiting either A or B symptoms. These symptoms refer to either the absence of A or presence of B unexplained weight loss in the preceding 6 months, fever greater than 38?C, and or night sweats.
Tumour suppressor genes: In health this family of genes usually act as a counter balance for oncogenesis. It is thought that they may be responsible for repairing gene damage in cells, or are growth inhibitor genes. In Hodgkin’s disease, there are often evidences of mutation in tumour suppressor genes as well as other genes.
Stage 1 Hodgkin’s disease affects a single lymph node or lymph node region. The lymph nodes most commonly affected are the nodes in the neck, armpits or groin.
Stage 2 disease is associated with lymph node involvement in 2 or more regions. However, the nodes must be involved in only one side of the diaphragm. The diaphragm is a muscle lying beneath the lungs. It moves up and down allowing air to move in and out of the lungs.
Stage 3 disease is associated with lymphoma involvement on both sides of the diaphragm. The spleen is frequently involved at this stage. If the spleen is involved the abdomen may become tender or enlarged, with or without symptoms of abdominal fullness and distension.
When Hodgkin’s disease enters stage 4, disease can spread through the body to area outside of the lymphatic system.
Disease may be present in the liver, bone marrow, gastrointestinal tract, lungs, brain or skin. Spread of disease into these organs can inhibit organ function, leading to organ failure. If Hodgkin’s disease spreads to the bones, the bones may become weak and brittle. And the lymph nodes in the centre of the chest may be enlarged causing obstruction of the superior venacava vein. This can result in the accumulation of fluid in the region of the chest causing severe swelling and breathing difficulties.
Futhermore spread to the lungs may cause airway obstruction resulting in shortness of breath and/or a persistent cough. If swollen nodes cause compression of the oesophagus, swallowing and eating may become difficult. If Hodgkin’s disease spread to bone marrow, the production of blood cells may be inhibited. This may result in anaemia.
Chemotherapy is the treatment of choice for individuals with stage 3 or 4 disease. Chemotherapy may be recommended in Stage 1 and 2 disease if b-type symptoms are present, or the tumours are large. Depending on the stage of disease, radiotherapy may be used in conjunction with chemotherapy to maximise cancer cell death. There are many different chemotherapy regimes used to treat Hodgkin’s disease.
Radiotherapy is conventionally the treatment of choice for early stage disease. Radiotherapy is targeted towards those areas affected by Hodgkins disease. Furthermore, areas adjacent to the affected lymph nodes may be treated. This ensures that cancer cell that have spread to other areas are also killed.
More advanced stages of disease are frequently treated with a combination of radiotherapy and chemotherapy. Similarly Stages 1 and 2 with B-type symptoms may require combination treatment. Radiotherapy also has a role in the treatment of bulky tumours or painful lesions affecting the bones or skin surfaces.
Hodgkin’s disease might first be suspected when a swollen lymph node fails to subside. At this point a doctor will perform a physical examination. During the examination, he or he may ask you questions regarding recent or previous illness. The doctor may wish to listen to the heart and lungs to judge their performance and assess for signs of infection. Palpation of the abdomen and lymph nodes can determine if the organs or lymph nodes larger than normal. The doctor may inspect the mouth and skin surfaces for signs of infection. Following this a number of tests may be ordered.
A Lymph Node Biopsy is performed to identify the malignant Reed-Sternberg cells characteristic of Hodgkin’s disease. A lymph node biopsy is performed, during which a sample of tissue is removed from the swollen lymph gland and examined under the microscope. More than one biopsy is needed because biopsies do not always detect cancerous cells.
In addition to identifying Reed-Sternberg cells, the doctor will classify the Hodgkin’s disease into 4 distinct pathological groups depending on the cellular structure of the tissue. These 4 groups are called lymphocyte predominant, nodular sclerosis, mixed Cellularity and lymphocyte depleted. Each group has a different prognosis. Furthermore, each group may present with different signs and symptoms.
? Lymphocyte Predominant
This group accounts for approximately 5% of all cases. It is associated with the most promising prognosis. It is more common in males and often occurs in the younger age group. Patients usually present with stage 1 or 2 disease and rarely suffer from B-type symptoms.
? Nodular Sclerosis
This group accounts for approximately 50% of all cases and is associated with a good prognosis. It is more common in females and regularly occurs in the 15-35 year age group. Patients usually present with stage 1 or 2 disease and rarely suffer from B-type symptoms.
? Mixed Cellularity
This group accounts for approximately 40% of all cases. It is associated with an intermediate prognosis. It is more common in males and is seen in the 30-40 year age group. Patients often present with stage 3 or 4 disease, the majority of which suffer from B-type symptoms. Disease is frequently found to have spread throughout the abdomen.
? Lymphocyte Depleted
This group accounts for approximately 5% of all cases. It is associated with the worse prognosis. It is most commonly seen in elderly males. Patients typically present with advanced staged disease and B-type symptoms. Lymphocyte depleted Hodgkin’s disease closely resembles non-Hodgkin’s lymphoma.
Anatomy and Physiology