Mantle Cell Lymphoma (MCL)

Lymphoma is the most common blood cancer. The two main forms of lymphoma are Hodgkin lymphoma and non-Hodgkin lymphoma (NHL). Lymphoma occurs when cells of the immune system called lymphocytes, a type of white blood cell, grow and multiply uncontrollably. Cancerous lymphocytes can travel to many parts of the body, including the lymph nodes, spleen, bone marrow, blood, or other organs, and form a mass called a tumor. The body has two main types of lymphocytes that can develop into lymphomas: B-lymphocytes (B-cells) and T-lymphocytes (T-cells).

Mantle cell lymphoma (MCL) is a rare, B-cell NHL that most often affects men over the age of 60. The disease may be aggressive (fast growing) but it can also behave in a more indolent (slow growing) fashion in some patients. MCL comprises about five percent of all NHLs. The disease is called “mantle cell lymphoma” because the tumor cells originally come from the “mantle zone” of the lymph node. MCL is usually diagnosed as a late-stage disease that has typically spread to the gastrointestinal tract and bone marrow.

A diagnosis of MCL requires taking a small sample of tumor tissue, called a biopsy, and looking at the cells under a microscope. A blood test may also be necessary to measure the white blood cell count and certain proteins, which help to diagnose MCL. Other tests, such as a bone marrow biopsy and a computed axial tomography (CAT) scan may be used to confirm a diagnosis and to determine what areas of the body are involved by the cancer.

Overproduction of a protein called Cyclin D1 is found in more than 90 percent of patients with MCL. Identification of excess Cyclin D1 from a biopsy is considered a very sensitive tool for diagnosing MCL. One-quarter to one-half of patients with MCL also have higher than normal levels of certain proteins that circulate in the blood, such as lactate dehydrogenase (LDH) and beta-2 microglobulin. Measuring these and other proteins can help doctors determine how aggressive an individual patient’s MCL is and may guide therapy decisions.