Introduction

Lymphomas are cancers of lymphocytes, which reside in the lymphatic system and in blood-forming organs.

Lymphomas are cancers of a specific type of white blood cells known as lymphocytes. These cells help fight infections. Lymphomas can develop from either B or T lymphocytes. T lymphocytes are important in regulating the immune system and in fighting viral infections. B lymphocytes produce antibodies.

Lymphocytes move about to all parts of the body through the bloodstream and through a network of tubular channels (lymphatic vessels (see Section 16, Chapter 183)). Scattered throughout the network of lymphatic vessels are lymph nodes, which house collections of lymphocytes. Lymphocytes that become cancerous (lymphoma cells) may remain confined to a single lymph node or may spread to the bone marrow, the spleen, or virtually any other organ.

The two major types of lymphoma are Hodgkin's lymphoma, more commonly known as Hodgkin's disease, and non-Hodgkin's lymphoma. Non-Hodgkin's lymphoma is a much more common disease than Hodgkin's disease. Burkitt's lymphoma and mycosis fungoides are subtypes of non-Hodgkin's lymphoma.