In a 45-year-old man with a long history of recurrent peripheral arthritis and a more recent history of gastrointestinal symptoms, a biopsy specimen obtained from the small intestine by means of the Shiner tube here described led to the diagnosis of intestinal lipodystrophy. The diagnosis was confirmed during an exploratory laparotomy, at which no other abnormalities were found. A characteristic finding under the microscope was the enlargement of the intestinal villi with distinctive, foamy-appearing mononuclear cells seen most commonly in the mucosa but also in the submucosal and subserosal layers. The patient recovered gradually on conservative treatment, including therapy with ACTH. The most recent episode of arthritis responded to increased ACTH dosage.