Abstract: Extra-nodal malignant lymphoma is often characterized by a lack of typical symptoms and positive results of
auxiliary examinations, which make diagnosis difficult. In some cases, fever can be the only clinical manifestation. For the
lymphoma patients presenting with persistent fever with a duration over 3 weeks, characteristics of fever including time of
fever attack, fever type and effects of drugs may have significant value in the diagnosis, especially in the early stage of the
disease or in rare cases.