[Non-Hodgkin's lymphoma: biologic classification, diagnosis and treatment]

The lymphomas are the seventh most common causes of death from cancer in the United States. There is a steady increase in the incidence of non-Hodgkin's Lymphoma from childhood through the age 80, and in the United States, is more common in males than in females. The etiology of the lymphomas is unknown. Molecular biology techniques have allowed the elucidation of many cellular function involved in tumorigenesis. Clinical presentation of non-Hodgkin's lymphoma are varied, and depend on the histologic subtype, the extent (or stage) of the disease, and the primary site of the tumor, most often present lymph node disease, children typically have extranodal disease involving the mediastinum, abdomen or head and neck. Non-Hodgkin's lymphoma are categorized as low, intermediate, or high grade, on the basis of their clinical aggressiveness. Low and intermediate grade tumors predominate in adults, whereas more than 90 percent of children with non Hodgkin's lymphoma have a high grade tumor. The field of cancer therapy has progressed rapidly. In the most recent era, treatment has included multiagent chemotherapy directed to the stage and histologic subtype of the disease. Gene therapy has now become a standard experimental approach for treating cancer were conventional therapies have failed.