This is a clinical practice guideline addressing lymphoma in the adult population. The guideline focuses on the following areas: Diagnosis and Pathologic Classification, Staging, Treatment of Non-Hodgkin Lymphomas, Hodgkin Lymphoma, HDCT and hematopoietic stem cell transplantation for lymphoma, supportive care in the treatment of lymphoma, and follow-up care in the treatment of lymphoma. Additionally, it seeks to provide recommendations to the following questions: what are the diagnostic criteria for the most common lymphomas; what are the staging and re-staging procedures for Hodgkin and non-Hodgkin lymphomas; what are the recommended treatment and management options for Hodgkin and non-Hodgkin lymphomas; and what are the recommended follow-up procedures for patients with malignant Hodgkin and non-Hodgkin lymphoma.