Ultrasound is most useful in detecting and characterizing peripheral and abdominal lymph nodes and infiltration of solid organs. B-mode criteria, such as size, shape, number, distribution architecture, echogenicity and delineation of margins are the basis for characterizing lymph nodes. Additionally color coding techniques such as color Doppler, B-flow and contrast-enhanced ultrasound (CEUS) contribute to the evaluation of the nodal vasculature and vessel architecture. Whenever possible high frequency probes should not only be used for evaluating peripheral lymph nodes but also for lymphatic infiltration of solid organs, especially the spleen. The CEUS technique will be of additional benefit in detecting characterizing potential lymphatic organ infiltration. Ultrasound is an ideal tool for guided punctures, for which core biopsies should be preferred over fine needle aspiration biopsy and CEUS can also be used for proving residual viable tissue after chemotherapy or radiation therapy.