Idiopathic pneumatosis cystoides coli: An uncommon cause of pneumoperitoneum.

Pneumatosis cystoides intestinalis (PCI) is a rare entity characterized by the presence of gaseous cystic within the intestinal wall. The primary or idiopathic type represents 15% of cases and is a self-limited or chronic benign entity. The secondary type represents 85% of cases and is associated with various factors, such as surgery, pharmacotherapy, chemotherapy, autoimmune diseases, inflammatory diseases, and pulmonary illness. Pneumatosis cystoides intestinalis affects the colon (pneumatosis cystoides coli) in about half of the cases. The differential diagnosis of PCI includes potentially life-threatening diseases that cause pneumatosis intestinalis. The misdiagnosis of PCI is common and can lead to unnecessary treatments and surgical procedures. We describe an asymptomatic pneumoperitoneum incidentally seen on chest radiograph. The cause was pneumatosis cystoides coli, which did not require treatment.