CLL and the other leukemias are primary disorders of the bone marrow, whereas, the lymphomas are malignant disorders that arise in the lymphoid tissue, most often showing up as solid tumors in nodes found throughout the body.

There are two broad groups of lymphomas: Hodgkin's disease (Hodgkin's lymphoma) and non-Hodgkin's lymphomas (NHL). Like the leukemias, Hodgkin's and non-Hodgkin's lymphomas are categorized into several sub-types.