Introduction: Inflammatory pseudotumor of lymph node is a rare case in the etiology of fever of unknown origin.
Observation: We report the observation of a woman, aged 40, hospitalized with intermittent fever revealing under-diaphragm adenopathy related to inflammatory pseudotumor of lymph node.
Conclusion: Inflammatory pseudotumor of lymph node is a rare pathology whose nosological definition is unclear. It should probably be considered as belonging to a category different from the inflammatory pseudotumor of other organs. The diagnosis presents itself in case of isolated adenopathy or prolonged fever and is based on an anatomopathology that essentially calls to mind a lymphoma. The evolution of the condition is shown to be favorable : it can lead to a spontaneous remission, or call for a non-steroid anti-inflammatory treatment, or a steroid therapy.