Rare causes of pneumoperitoneum.

Pneumoperitoneum is defined as the presence of free air within the peritoneal cavity. In approximately 90% of cases, it results from gastrointestinal perforation and requires urgent surgical intervention. The remaining 10% represent nonsurgical (spontaneous) pneumoperitoneum, in which no perforation is detected and conservative management is usually sufficient. Etiologically, nonsurgical pneumoperitoneum can be classified into pseudopneumoperitoneum, intrathoracic, abdominal, gynecological, and idiopathic categories. Intrathoracic causes include air migration from the chest during mechanical ventilation, cardiopulmonary resuscitation, or spontaneous pneumothorax. Abdominal causes involve rupture of cysts in pneumatosis cystoides intestinalis, perforation of hepatic or splenic abscesses, barotrauma, endoscopic complications, and infections by gas-producing bacteria. Gynecological causes are associated with vaginal insufflation, sexual intercourse, or instrumentation. In a minority of cases, the etiology remains idiopathic. Differentiating between surgical and nonsurgical pneumoperitoneum is crucial, as unnecessary laparotomies are reported in up to one quarter of patients. Decision--making requires comprehensive clinical evaluation, thorough physical examination, and imaging studies, particularly contrast-enhanced CT. In the absence of peritonitis or sepsis, conservative management with observation, antibio-tics, and symptomatic therapy is recommended. Accurate dia-gnosis and awareness of the rare, nonsurgical causes of pneumoperitoneum are essential to prevent unnecessary surgical interventions and to optimize patient care in this potentially critical condition.