Lymphomas are a heterogeneous group of tumors arising in the reticuloendothelial and lymphatic systems. The major types are
Hodgkin lymphoma
Non-Hodgkin lymphoma
See table .
Lymphomas were once thought to be absolutely distinct from leukemias Overview of Leukemia Leukemia is a malignant condition involving the excess production of immature or abnormal leukocytes, which eventually suppresses the production of normal blood cells and results in symptoms... read more . However, better understanding of cell markers and tools used to evaluate those markers now show that the distinction between these 2 cancers is often vague. The notion that lymphomas are relatively restricted to the lymphatic system and leukemias to the bone marrow, at least in early stages, is not always true. Malignant lymphoma cells can populate the bone marrow and the blood as well as the lymph nodes.