Slow-growing lymphomas are subdivided into numerous B-cell and T-cell subtypes, for example:
Small lymphocytic / pro-lymphocytic lymphoma (SLL)
Large granular lymphocyte leukemia
Adult T-cell leukemia/lymphoma (ATL/L )
Mycosis fungoides/Sézary Syndrome
Small lymphocytic/prolymphocytic lymphoma (B-SLL) represents only about 4 percent of adult NHL. It usually occurs in adults with generalized lymph node disease (lymphadenopathy). This disease manifests more often as B-cell chronic lymphocytic leukemia (B-CLL) than as B-SLL. An increased rate of cell division is associated with more aggressive disease and a shorter survival time.
The lymph node cells of SLL may transform into an aggressive, large B-cell lymphoma in as many as 15 percent of patients. This is known as Richter's syndrome. In addition, B-CLL/SLL may undergo a Hodgkin's-like transformation.
Follicular lymphoma represents 70 percent of all the low-grade B-cell lymphomas. It is the second most common lymphoma in the United States and comprises 20 percent of all NHL. Men and women are affected in nearly equal numbers, and the average age of onset is 55 years.
Most patients tend to have widespread, advanced-stage disease at diagnosis. Despite this fact, the disease is slow to progress, although tumor grade may play a role in disease behavior. Only one-quarter of affected individuals develop B symptoms. The bone marrow becomes a site of disease spread in nearly half of all patients.
Transformation to an aggressive lymphoma is a frequent, deadly consequence of this disease. In such cases, the follicular pattern changes from a low percentage of large cells to a more diffuse pattern with primarily large cells.
In many patients, lymphoplasmacytoid lymphoma conforms to the clinical picture of Waldenstrom's macroglobulinemia, a progressive syndrome that affects the endothelium (lymphatic system lining). In this disorder, the lymphoma cells produce excessive amounts of an antibody known as immunoglobulin M (IgM). As a result, the abnormally high IgM level makes the blood thick and unable to flow properly.
The kidneys may be damaged, and the individual may experience symptoms such as poor vision (due to inadequate circulation in the blood vessels of the eyes), fatigue, easy bleeding, headaches, and dizziness. The disease tends to occur in males more often than in females, and the average age of onset is 63 years.
The lymph nodes and spleen frequently are involved, and about 75 percent of patients also have involvement of the bone marrow. This disease typically is slow growing.
Marginal zone B-cell lymphoma is another lymphoma that tends to progress slowly. If this disease directly affects the lymph nodes, it is called monocytoid B-cell lymphoma; however, if it affects lymphatic tissues at other sites (e.g., stomach, thyroid, skin), it is called mucosa-associated lymphatic tissue, or "MALT" lymphoma. Most low-grade gastric (stomach) lymphomas, and nearly half of all other gastric lymphomas, are marginal zone B-cell lymphomas.
Extranodal (outside the lymph nodes) marginal zone tumors may arise in the stomach as well as the lungs, eye sockets, intestines, thyroid, salivary gland, bladder, kidney, and even the central nervous system (CNS). This type of lymphoma affects more women than men, and the average age at diagnosis is 65 years.
The majority of patients are diagnosed with localized, early-stage (Stage 1 or 2) extranodal disease. Many patients have a history of autoimmune disease (disease caused by the body's immunologic attacks against its own tissues) such as Sjögren's syndrome or Hashimoto's thyroiditis, or bacterial infection of the stomach with Helicobacter pylori. Research findings suggest that antibiotic therapy for Helicobacter pylori infection may prolong remission in early gastric MALT lymphoma.
Splenic marginal zone lymphoma is a rare, slow-growing cancer. It also is known as "splenic lymphoma with villous lymphocytes"an uncommon form of B-cell chronic lymphocytic leukemia (B-CLL). Splenic marginal zone lymphoma typically involves the spleen and is considered the splenic counterpart of MALT lymphoma. This lymphoma occurs in adults and is slightly more frequent in women than in men.
Patients usually have splenomegaly (enlarged spleen) without enlargement of the peripheral lymph nodes. Most patients show bone marrow involvement and modest increases in blood lymphocyte counts.
Adult T-cell leukemia/lymphoma (ATL/L) is a unique cancer that originally was identified in the population of southwestern Japan. It is associated with the retrovirus HTLV-1, which infects the T-cells. ATL/L also is common among Caribbean people, and it has been diagnosed in black residents of the southeastern United States. The average age of diagnosis is 45 years.
Patients may exhibit leukemia or generalized enlargement of the lymph nodes. The leukemic form of this disease is more common in Japan, whereas the lymphatic form is more common in the Western hemisphere.
Mycosis fungoides is a rare skin-based (cutaneous) lymphoma that accounts for only 2 to 3 percent of all NHLs. Skin effects may appear as numerous plaques (flat patches) or nodules (knot-like masses) with/without redness.
Sézary syndrome is an aggressive variety of this disease that causes widespread reddening of the skin. Lymph node enlargement is uncommon but, when present, usually signals a poor prognosis (disease outcome). This lymphoma is most often diagnosed in older adults (age 55 to 60 years), and men are twice as likely to be affected as women. The cause of mycosis fungoides is unknown.
Large granular lymphocyte leukemia (LGL) is a cancer that is related to T-cell chronic lymphocytic leukemia (T-CLL). In general, LGL is not considered with other cases of malignant lymphoma.