Conservative management of idiopathic pneumoperitoneum masquerading as peritonitis: report of a case.

Pneumoperitoneum is most commonly caused by the perforation of a hollow viscus, in which case an emergency laparotomy is indicated. We report herein the case of a patient who presented with the signs and symptoms of peritonitis, but who was found to have idiopathic pneumoperitoneum which was successfully managed by conservative treatment. A 70-year-old man presented with epigastric pain, nausea, and a severely distended and tympanitic abdomen. Abdominal examination revealed diffuse tenderness with guarding, but no rebound tenderness. He was febrile with leukocytosis and high C-reactive protein. Chest X-ray and abdominal computed tomography demonstrated a massive pneumoperitoneum without pneumothorax, pneumomediastinum, pneumoretroperitoneum, or subcutaneous emphysema, and subsequent examinations failed to demonstrate perforation of a hollow viscus. Thus, a diagnosis of idiopathic pneumoperitoneum was made, and the patient was managed conservatively, which resulted in a successful outcome. This experience and a review of the literature suggest that idiopathic pneumoperitoneum is amenable to conservative management, even when the signs and symptoms of peritonitis are present.