[A case of nonsurgical pneumoperitoneum associated with the incomplete type of intestinal Behçet disease].

A 58-year-old man was admitted with fever and arthralgia. He had some symptoms suggesting the incomplete type of Behçet disease, and a routine chest X-ray films showed the presence of massive pneumoperitoneum (PP). Exploratory laparotomy revealed no evidence of gastrointestinal perforation or peritonitis. Thus, we initially diagnosed it as idiopathic PP. However a 2×1-mm induration located on the antimesentric side of the ileum 50cm proximal to the ileocecal valve. The wedge-shaped pathological specimen showed ulcer perforation and its restoration. Finally we concluded it to be nonsurgical PP. This case provides significant information on the etiology of idiopathic PP.