Learn About Lymphoma

Lymphomas are cancers of a type of white blood cell called a lymphocytes. About 70,000 people in the United States each year will be diagnosed with lymphoma. Lymphomas usually show up in lymph nodes but as they come from white blood cells (cells of the immune system) they can show up in any part of the body. There are many different kinds of lymphomas that have different names, can show up in a person in different ways, have different treatments, and different outcomes. You can subdivide or classify the different types of lymphomas in many ways. You can divide them between Hodgkin lymphoma and non-Hodgkin lymphoma. Among the non-Hodgkin lymphomas you can divide them according to the type of lymphocyte they come from. Normal lymphocytes come in a few different varieties–mostly B cells and T cells. B cells and T cells have different jobs in the immune system. If a normal B-cell becomes a cancer we call that a B-cell lymphoma and if a normal T-cell becomes a cancer we call that it T-cell lymphoma.

About 90% of non-Hodgkin’s lymphomas will be B-cell lymphomas and about 10% will be T-cell lymphomas. Even among the T-cell lymphomas there are more than 20 different kinds. Normal T cells in the body can be divided according to their job in the immune system. Most T cells in the body are what we call alpha-beta T cells. Though there are a subset of T cells in the body called gamma-delta T cells. When gamma-delta T cells become a lymphoma we call them gamma-delta T-cell lymphomas. These are very rare lymphomas, making up less than 10% of all the T-cell lymphomas or less than 1% of all non-Hodgkin lymphomas.

Gamma-delta T-cell lymphomas tend to show up outside of lymph nodes, most commonly in the skin or the liver, spleen, and bone marrow. The gamma-delta T-cell lymphoma that show up in the skin are called cutaneous gamma-delta T-cell lymphomas and the ones that show up in the liver, spleen, and bone marrow are called hepatosplenic T-cell lymphomas. In general most gamma-delta T-cell lymphomas have an aggressive behavior. Aggressive behavior for a lymphoma means that the lymphoma grows relatively quickly, usually over months, and if not treated can become dangerous or life-threatening. Because T-cell lymphomas are so uncommon and in particular gamma-delta T-cell lymphomas are so rare, research in finding new treatments has lagged behind that of B-cell lymphomas and other cancers. Currently we treat gamma-delta T-cell lymphomas with chemotherapy, including several new therapies for T-cell lymphomas. However many of the treatments used for other lymphomas do not work as well for people with gamma-delta T-cell lymphoma. Even when chemotherapy or other treatment can reduce or get the gamma-delta T cell lymphomas into remission–they tend to recur quickly. Currently a stem cell or bone marrow transplant is the only treatment we have that can reliably cure people with gamma-delta T-cell lymphomas. This treatment carries a lot of risk and even then it doesn’t work all the time. Research to develop a better understanding of gamma delta T-cell lymphomas (and T-cell lymphomas in general) and develop new, more successful treatments is underway but progress can’t move quickly enough.