[Kikuchi disease and lupus: case report, literature review and FDG PET/CT interest]

Kikuchi disease is a rare entity characterized by lymphadenopathy and fever. Pathology study of lymph node biopsies provides the diagnosis. The disease course is favorable. The disease can occur isolated, or associated with other pathologies including lupus or mixed connective tissue disease. We report a case of Kikuchi disease in a 35-year-old woman, occurring 12 years after the diagnosis of overlap syndrome with antiphospholipid antibodies. The patient was given prednisone 25mg per day and long-term hydroxychloroquine. FDG PET/CT showed FDG-avidity nodular masses. After bolus corticosteroid therapy, outcome was favorable with disappearance of metabolic hyperactivity on the FDG PET/CT. The bolus prednisone treatment could then be discontinued. In the 61 cases of Kikuchi disease and lupus associations previously published, Kikuchi disease was diagnosed after lupus in only 13 % of the observations. In these cases, use of FDG PET/ CT was not reported. For us, FDG PET/CT was useful for diagnosis, for choosing the biopsy site and for follow-up.