I. Lymph node aspiration and biopsy Malignant lymphoma has a wide variety of clinical manifestations, and pathological examination is required to make a clear diagnosis. The purpose of pathological examination is twofold: (i) to confirm malignant lymphoma and pathological subtypes from cell morphology and pathological features; (ii) immunological examination can clarify the source of malignant lymphoma (T cells or B cells). Lymph node aspiration smear examination is a simple and easy method that requires no special equipment, less chance of bleeding and infection, less pain for the patient, and rapid diagnosis as long as pathological tissue is available. However, the limitations of the specimens obtained by puncture smear pose certain difficulties for the reliability of the diagnosis. Lymph node biopsy can further clarify the various subtypes of lymphoma, so it should be the first choice as long as clinical conditions are available. Lymph node puncture and lymph node biopsy are not only necessary before the patient’s diagnosis is confirmed, but also for some inert lymphomas, which can evolve into aggressive lymphomas due to disease progression. Therefore, once the disease is suspected to be inconsistent with the symptoms of inert lymphoma, lymph node biopsy should be performed again to understand the changes of the disease. Bone marrow aspiration and biopsy Bone marrow aspiration is a common diagnostic technique for extracting bone marrow fluid, through which the invasion of bone marrow by malignant lymphoma can be understood. Bone marrow biopsy can understand the whole picture of bone marrow histopathology to supplement the deficiency in bone marrow aspiration examination. Stomach, spleen and liver examination Some lymphoma lesions may involve extra-lymph node tissues and organs. In these patients, the only way to understand the extra-lymph node invasion is to obtain the corresponding pathological diagnosis through corresponding examinations, such as gastroscopy, enteroscopy, spleen and liver biopsy. Lumbar puncture Lumbar puncture is a diagnostic technique for understanding central nervous system lesions. Malignant lymphoma, especially in T-lymphoma, often involves the central nervous system. Lumbar puncture can not only clarify whether the lymphoma invades the central nervous system, but also treat malignant lymphoma of the central nervous system. Lumbar puncture must be repeated until the cerebrospinal fluid examination is in the normal range, and regular prophylactic treatment is given later. V. Imaging examination Malignant lymphoma mainly invades the lymph nodes, and the enlarged lymph nodes will gradually shrink with various treatment methods. Routine blood test Routine blood test can understand the peripheral blood erythrocyte, white blood cell and platelet count lymphocyte count. After chemotherapy, white blood cell and platelet counts may drop, and it often takes about 10 to 14 days to recover, so routine blood tests can understand the recovery situation to determine whether the next chemotherapy can be carried out. Serum lactate dehydrogenase and blood urine-microglobulin (MG) Serum lactate dehydrogenase and blood urine a1-MG are often related to the load of tumor, and the load decreases significantly after treatment, and serum lactate dehydrogenase and blood urine a1-MG will also decrease accordingly.