In primary lymph node cancer or lymphoma, the cells of the lymph nodes (lymphocytes) become cancerous resulting in abnormal and excessive proliferation or growth of the tissues and cells of the lymph nodes. This causes enlargement of lymph nodes in various parts of the body and these swollen lymph nodes are most often detected in the armpit, neck or groin as painless, hard swellings.
Lymphomas are usually restricted within the lymph nodes or other lymphatic tissue but may sometimes spread to other types of tissues in the body, where it is known as extranodal disease.
There are two types of lymphomas – Hodgkin’s lymphoma and non-Hodgkin lymphomas. The latter, non-Hodgkin lymphomas, includes all other lymphomas which are not Hodgkin’s lymphoma. These are further divided into five subtypes of Hodgkin’s lymphoma and about 30 subtypes of non-Hodgkin lymphoma based upon their microscopic appearance, genetic arrangement or extent of the disease process.
