Any benign or malignant disease in which lymphocytes or lymphatic tissues proliferate. Included are self-limited proliferation of lymph glands, lymphocytes, and monocytes; infectious mononucleosis; benign abnormalities of immunoglobulin synthesis; leukemias; lymphomas such as Hodgkin’s disease, lymphosarcoma, reticulum cell sarcoma, and mycosis fungoides; malignant proliferative response or abnormal immunoglobulin synthesis such as plasma cell myeloma, macroglobulinemia, and amyloidosis; histiocytosis; and lipid storage disease,