The term lymphoma encompasses more than 40 related types of cancer that develop from lymphocytes (cells of the immune system). Lymphoma arises when one of these cells undergoes a transformation into a malignant cell and begins to grow abnormally, dividing and forming tumors.
Lymphocytes, critical cells in the immune system, originate in the bone marrow and thymus, a small organ in front of the heart. These cells circulate in the blood and lymph and reside in the lymph nodes and in the other organs of the lymphatic system -- the spleen, thymus, tonsils, and bone marrow, which are generally affected first in patients with lymphoma.
Types of Lymphomas
Lymphomas are divided into two general types: Hodgkin's disease and non-Hodgkin's lymphomas. Combined, the non-Hodgkin's lymphomas are much more prevalent than Hodgkin's disease. Since the early 1970s, the incidence of non-Hodgkin's lymphomas has doubled in the United States; the greatest increase has occurred among the elderly. Only lung cancer in women and melanoma have increased more rapidly. Over the same period, Hodgkin's disease has declined -- particularly among the elderly.
Non-Hodgkin's lymphomas may be aggressive (also known as intermediate or high-grade lymphomas) or indolent (also known low-grade lymphomas).
The Genetics of Lymphoma
Memorial Sloan-Kettering researchers are working to improve the understanding of the genetic causes of Hodgkin's disease and non-Hodgkin's lymphoma, as well as multiple myeloma, leukemia, and related diseases. The goal of the research is to identify genetic changes that may predict the risk of developing one of these diseases.
