Lymphoma is the most common form of cancer in the blood and lymph system. It originates in lymph cells everywhere in the body and is separated into two main groups:
- Hodgkin's lymphoma (HL)
- Non-Hodgkin lymphoma (NHL)
HL and NHL are further separated into more than 30 subgroups of importance for treatment and prognosis. Five subgroups belong to HL and the rest are subgroups of NHL.
Characteristic aspects of HL are Reed-Sternberg cells (RS) or large Hodgkin cells in an inflammatory environment. RS and Hodgkin's cells appear to be resistant to apoptotic stimuli. These cells are essential for diagnosing HL.
Lymphoma comprises about 4% of new cancer cases, and the incidence is increasing. Many patients are cured, but there is also a large number of patients living with the disease over long periods. Thus, lymphoma patients are overrepresented among long-term survivors and among patients in need of follow-up even for years after the diagnosis is made.