These are malignant tumours of lymphoid tissue and are classified as either Hodgkin’s or non-Hodgkin’s lymphomas.
HODGKIN’S DISEASE.
In this disease there is progressive,painless enlargement of lymph nodes throughout the body,as lymphoid tissue within them proliferates. The superficial lymph nodes in the neck are often the first to be noticed. The disease is malignant and the cause is unknown. The prognosis varies considerably but the pattern of spread is predictable because the disease spreads to adjacent node and to other tissues in a consistent way. The effectiveness of treatment depends largely on the stage of the disease at which it begins. The disease leads to reduced immunity,because lymphocyte function is depressed,and recurrent infection is therefore common. As lymph nodes enlarge,they may compress adjacent tissues and organs. Anaemia and changes in leukocytes numbers occur if the bone marrow is involved.
NON-HODGKIN’S LYMPHOMAS.
These tumours,eg.multiple myeloma and Burkitt’s lymphoma,may occur in any lymphoid tissue and in bone marrow. They are classified according to the type of cell involved and the degree of malignancy,ie. low,intermediate or high grade.
Low-grade tumours consist of well differentiated cells and slow progress of the disease,death occurring after a period of years.
High-grade lymphomas consist of poorly differentiated cells and rapid progress of the disease,death occurring in weeks or months. Some low or immediate grade tumours change their status to high grade with increased rate of progress.
The expanding lymph nodes may compress adjacent tissues and organs. Immunological ,and if the bone marrow or spleen(or both) is involved there may be varying degrees of anaemia and leukopenia.
