Abstract
A 59-year-old woman with epilepsy was admitted to hospital with a 6-year history of fever of unknown origin (FUO). Computed tomography (CT) showed extensive low-attenuation mesenteric and retroperitoneal lymphadenopathy. Investigations for malignancy and infection were negative, including two separate excisional biopsies of lymph nodes. An ascending aortic aneurysm was seen on CT, and a diagnosis of large vessel vasculitis (LVV) was considered. A trial of prednisone for presumed LVV was initiated and then discontinued when positron emission tomography (PET) failed to show vasculitis. Repeat core biopsy of a mesenteric lymph node revealed non-necrotizing granulomatous inflammation and histiocytes with periodic acid-Schiff (PAS)-positive intracellular material. Electron microscopy and polymerase chain reaction (PCR) of the tissue confirmed Tropheryma whipplei. She was treated with ceftriaxone for 2 weeks, followed by long-term combination doxycycline and hydroxychloroquine. The patient's seizure control improved on therapy, raising the suspicion that the seizure disorder was due to Whipple's disease.