A 49-year-old woman with systemic lupus erythematosus (SLE) had persistent abdominal pain and fullness for days. A Ga-67 can showed an area of increased radioactivity in the central abdomen. Computed tomography revealed an abnormal high-attenuation soft tissue area in the mesentery. Mesenteric vasculitis was diagnosed. Her symptoms and signs subsided rapidly after the administration of dexamethasone.