Principles of diagnosis, staging and management

· The diagnosis of Hodgkin's disease (HD) or non-Hodgkin's lymphoma (NHL) must be based on a tissue biopsy. Re-biopsy should be performed at each recurrence when possible. · The new WHO classification of NHL takes into consideration immunophenotype (90% of lymphomas are B-cell origin), cytogenetics and molecular biology. · ″Staging investigations″, i.e. CT scans and a bone marrow aspirate and trephine biopsy, should be performed at presentation and at recurrence to determine the extent and distribution of disease. · Treatment will depend on histological subtype, stage, and the age and performance status of the patient. · Patients with HD, diffuse large B-cell NHL and lymphoblastic lymphoma/Burkitt's lymphoma are treated with curative intent. In other subtypes of NHL, recurrence is virtually inevitable with conventional therapy. · Imaging is essential for staging, assessment of response and in the diagnosis of relapse. Standardized response criteria have been developed, and should be adopted for clinical usage.