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.
Comparison of Hodgkin Lymphoma and Non-Hodgkin Lymphoma
Feature | Hodgkin Lymphoma | Non-Hodgkin Lymphoma |
|---|---|---|
Nodal involvement | Typically localized to a specific group of nodes | Usually disseminated among > 1 nodal group |
Spread | Tends to spread in an orderly, contiguous fashion | Spreads noncontiguously |
Effect on Waldeyer ring and mesenteric lymph nodes | Usually does not affect | Commonly affects mesenteric nodes May affect Waldeyer ring |
Extranodal involvement | Infrequent | Frequent |
Stage at diagnosis | Often early | Usually advanced |
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.
