Malignant Lymphomas

Also called non-Hodgkin's lymphomas and lymphosarcomas, malignant lymphomas are a heterogeneous group of malignant diseases that originate in lymph glands and other lymphoid tissue. A chronic form of T-cell lymphoma originates in the skin.

Lymphomas are usually classified according to histologic, anatomic, and immunomorphic characteristics developed by the National Cancer Institute. However, the Rappaport histologic and Lukes classifications also are used in some settings.

Malignant lymphomas occur three times more commonly than Hodgkin's disease, and the incidence is increasing, especially in patients with autoimmune disorders and those receiving immunosuppressant treatment. Nodular lymphomas yield a better prognosis than the diffuse form of the disease, but in both, the prognosis is less hopeful than in Hodgkin's disease.

Causes

Although some theories point to a viral source, the cause of malignant lymphomas is unknown.

Signs and Symptoms

he signs and symptoms may differ, depending on the location of the involvement. Patients may experience loss of appetite, weight loss, nausea, vomiting, abdominal discomfort, and indigestion. The patient may complain of a feeling of fullness, which is a result of enlarged lymph nodes in the abdomen. Sometimes the abdomen can become so swollen it may resemble pregnancy in a woman. Pressure or pain in the lower back is another symptom. Since all the symptoms are common to many other illnesses, it is essential to seek medical attention if any of the conditions persist for two weeks or more. Only a qualified physician can correctly diagnose if the symptoms are due to lymphoma or some other ailment.

Diagnostic tests 

Biopsies - of lymph nodes; of tonsils, bone marrow, liver, bowel, or skin; or, as needed, of tissue removed during exploratory laparotomy - differentiate a malignant lymphoma from Hodgkin's disease. Chest X-rays; lymphangiography; liver, bone, and spleen scans; a computed tomography scan of the abdomen; and excretory urography indicate disease progression.

Treatment

Radiation and chemotherapy are the main treatment for lymphomas. Radiation therapy is used mainly during the localized stage of the disease. Total nodal irradiation often effectively treats both nodular and diffuse lymphomas.

Chemotherapy is most effective with combinations of antineoplastic agents. For example, the CHOP protocol (cyclophosphamide, doxorubicin, vincristine [Oncovin], and prednisone) can induce a complete remission in 70% to 80% of those with nodular lymphoma and in 20% to 55% of those with diffuse lymphoma. Other combinations such as MACOPB (methotrexte, leucovorin, doxorubicin [Adriamycin], cyclophosphamide, vincristine [Oncovin], prednisone, and bleomycin) can induce a prolonged remission and possibly a cure for diffuse lymphoma.

Because perforation commonly occurs in patients with gastric lymphomas, these patients usually undergo a debulking procedure before chemotherapy, such as a subtotal or, in some cases, a total gastrectomy.

Prevention

Although many cancers may be prevented by making diet and life style changes which reduce risk factors, there is currently no known way to prevent lymphomas. Protecting oneself from developing AIDS, which may be a risk factor for lymphomas, is the only preventive measure that can be practiced.

At present, there are no special tests that are available for early detection of non-Hodgkin's lymphomas. Paying prompt attention to the signs and symptoms of this disease, and seeing a doctor if the symptoms persist, are the best strategies for an early diagnosis of lymphoma. Early detection affords the best chance for a cure.