Hodgkin's Disease - Introduction

(Page 2)

Nodular Lymphocyte-Predominant Hodgkin's Disease. Nodular lymphocyte-predominant Hodgkin's disease occurs in about 5% of patients. It is distinct from classical Hodgkin’s lymphoma. The cells look like and are referred to as “popcorn” cells, which are variants of Reed-Sternberg cells. This type of HD typically affects younger patients and usually originates in the neck lymph nodes. It is sometimes confused with non-Hodgkin’s lymphoma (NHL). In fact, there is a 3 - 5% risk that nodular lymphocyte-predominant Hodgkin’s disease can transform into diffuse large B-cell NHL.

The Lymphatic System

Lymphomas are tumors of the lymphatic system. This system is a network of organs, ducts, and nodes. The lymphatic system transports a watery clear fluid called lymph throughout the body. The lymphatic system contains lymphocytes, which are important cells involved in defending the body against infections.

---

---

Lymphocytes. Lymphocytes, which are white blood cells, are a primary component of the immune system.

• Lymphocytes develop either in the bone marrow (called B cells or bone marrow-derived cells) or in the thymus gland (called T cells or thymus gland-derived cells).
• Both leukemia and lymphomas (Hodgkin’s disease and non-Hodgkin’s lymphomas) are cancers of lymphocytes. The difference is that leukemia starts in the bone marrow while lymphomas originate in lymph nodes and then spread to the bone marrow or other organs.

Lymphatic vessels. Lymphatic vessels begin as tiny tubes. These tubes collect and carry fluids that leak from body tissues, lymphocytes, proteins, and other substances collected from the body's tissues. The tubes lead to larger lymphatic ducts and branches, which drain into two ducts in the neck, where the fluid re-enters the bloodstream.

Lymph Nodes. Along the way, the fluid passes through lymph nodes, which are oval structures made up of lymph vessels, connective tissue, and white blood cells.

• The normal size of a lymph node varies from that of a pinhead to a bean. Most nodes are clustered throughout the body. Node clusters are found in the neck, lower arm, armpit, and groin, as well throughout the inside of the body.
• In a lymph node, lymphocytes are first exposed to foreign substances, such as bacteria. This exposure prompts the lymphocytes to produce antibodies, which target and attack these foreign proteins (antigens). More lymphocytes may also be made in the lymph node and added to the contents of the lymph fluid.
• Lymphocytes from elsewhere in the body may also be filtered out of the lymph fluid into the lymph node.