Overview of Lymphomas

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 Comparison of Hodgkin Lymphoma and Non-Hodgkin Lymphoma.

Lymphomas were once thought to be absolutely distinct from leukemias. 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.