Describe the incidence.
Incidence: NHL is the most common hematopoietic neoplasm.
The incidence of all NHLs increases with age; the peak incidence is in those aged > 50 years.
High-grade lymphomas are most common in children and young adults (20–40 years).
Chromosomal translocations: most commonly t(14;18)
Helicobacter pylori: associated with gastric lymphoma, e.g., MALT lymphoma, diffuse large B-cell lymphoma (DLBCL)
Autoimmune diseases: Hashimoto thyroiditis, rheumatoid arthritis
Immunodeficiency: congenital immunodeficiencies, AIDS, history of chemotherapy and/or immunosuppressive therapy
Environmental factors: aromatic hydrocarbons (e.g., benzene), radiation