The term lymphoma encompasses both Hodgkin and non-Hodgkin lymphoma and comprises
several lymphoproliferative malignant diseases with remarkable biological and clinical heterogeneity.
Hodgkin lymphoma is recognized by the presence of Reed-Sternberg cells in involved tissues and
almost all cases are originated from B-cells. Non-Hodgkin lymphomas are also predominantly derived
from B-cells, and only 12% of the cases have a T-cell or NK-cell origin. Non-Hodgkin lymphomas do
not present any characteristic cell type and the great majority of the cells in the tumor are clonally
derived from a transformed precursor. In this chapter, the biology, cellular origin and molecular
pathogenesis of lymphomas are discussed, focusing on the most common subtypes of B-cell non-
Hodgkin lymphomas. Selected topics of the epidemiology, clinical presentation and diagnosis of
lymphomas are also introduced, and an overview of the main issues related to pretreatment evaluation,
staging and treatment of lymphomas is provided.
Keywords: Lymphoid tissues, B-cell lymphomas, immunoglobulin genes, Mantle cell lymphoma, 9p21
deletion, Indolent lymphomas, Aggressive lymphomas, Diagnosis of Hodgkin lymphoma, Staging and
Pretreatment of Lymphomas, Evaluation of Lymphomas, Treatment and Prognosis of Lymphomas.
