The mantle zone is a section of the lymph cortex that surrounds the germinal center of the lymph node. A circle of small lymphocytes composes the mantle zone or corona of the lymph node. Germinal centers in the lymph nodes are the location of the proliferation, differentiation, and mutation of mature centroblasts or B-lymphocytes necessary for a properly functioning immune system. The humoral immune response (HIR) begins below this zone in the germinal center of the lymph node. B-cells in the mantle zone are transformed into antibody secreting plasma cells or memory cells after stimulation by a secondary antigen, such as those found on the surfaces of many microbes.
A benign condition that causes the growth of the mantle zone is called Castleman’s disease, also referred to as angiofollicular lymph node hyperplasia. One variety of the condition is unicentric, which means the zone of a single lymph node has a non-cancerous growth within it. Most physicians will recommend the surgical removal of the lymph node and a follow-up appointment to ensure the growth has not redeveloped.
Another type of benign mantle zone expansion is called multicentric, which is characterized by the development of benign growths in multiple locations lymph nodes throughout the body. A person with multicentric Castleman’s disease (MCD) may have other underlying conditions such as acquired immunodeficiency syndrome (AIDS), human immunodeficiency virus (HIV), or Kaposi’s sarcoma. Although there is not a standard treatment for MCD, some patients respond well to treatment with corticosteroid therapy and chemotherapy.
One of the most uncommon types of non-Hodgkin’s lymphoma, a cancer called mantle cell lymphoma (MCL), develops in the mantle of the lymph nodes. The lymphocytic cells in the mantle zone begin to divide before they are mature. These young cells continue to replicate and begin to accumulate in the lymphatic system. Eventually, the entire immune response is compromised.
Most people diagnosed with MCL are males who are at least 60 years old. Unexplained weight loss, night sweats, persistent fevers, and swollen lymph nodes are often the first symptoms a person will notice. The lymph node growth may feel like a small marble and is usually located on the neck, in either armpit, or on each side of the groin.
Diagnostic tests for MCL include computerized tomography (CT) scans of the chest, abdomen, and pelvic region. Blood and bone marrow are often tested for the presence of cancerous cells. A diagnosis occurs after the lymph node is surgically removed and examined in a laboratory. Treatment usually includes chemotherapy, radioimmunotherapy, immune based therapy, and the use of biologic agents to destroy the cancer. Another treatment method involves chemotherapy, then total body irradiation (TBI) to destroy the immune system, followed by a stem cell transplant to rebuild the immune system.