Lymphomas classically manifest themselves in the lymph nodes but can also present in other bodily tissues or systems; the organ where exactly they present may make a very great difference to the strategy that should be adopted for their management. This topic has only recently been consistently addressed as an issue on its own, apart from the rest of the lymphomas, and this text is the first to apply modern systems of classification, diagnosis and management. This text is essential reading for hematologic oncologists and hematopathologists.