Spontaneous pneumoperitoneum, described as the presence of air confined to the inner layer of the abdominal wall and external to the parietal peritoneum, may masquerade as true pneumoperitoneum [
1], thereby representing a diagnostic pitfall. It should be recognized that extraluminal intra- or retroperitoneal air rarely occurs without gastrointestinal tract perforation. It is associated with various causes, such as mechanical ventilation and pulmonary barotrauma, peritoneal lavage before computed tomography (CT), pneumothorax, chest injury, entry of air via the female genital tract, and intraperitoneal laceration of the bladder secondary to cystography [
1,
2]. A repeat CT examination within 6–8 h may help determine the significance of less specific signs of bowel and mesenteric injuries, such as focal bowel wall thickening, mesenteric fat stranding with focal fluid and hematoma, and intraperitoneal or retroperitoneal fluid [
3]. Thus, reevaluation with additional CT findings that are indicative of gastrointestinal tract perforation may strengthen the significance of the extraluminal free air.