1619 Not All Intra-Peritoneal Free Air Is Created Equal. Pneumatosis Cystoides Intestinalis Causing Massive Pneumoperitoneum After a Colonoscopy, a Benign Finding

Abstract

INTRODUCTION: Pneumoperitoneum is the presence of free air in the peritoneal cavity. Visceral perforation, obstruction, and infection are the most ominous causes and usually present with signs of acute peritonitis requiring emergent surgery. CASE DESCRIPTION/METHODS: A 60-year-old man was found to have extensive colonic wall bullae (pneumatosis coli) in the transverse colon during a colonoscopy (Figure 1). Contrast-enhanced abdominal computed tomography (CT) 6 days later detected free air in the peritoneal cavity, the umbilical subcutaneous fat, and pneumatosis intestinalis in the distal transverse colon (Figure 2). Patient reported mild abdominal distension which quickly improved, otherwise he was asymptomatic. His abdomen was distended, but benign with no signs of peritoneal irritation. His laboratory work was unremarkable with normal white blood cell count and lactic acid. He was managed conservatively with nothing by mouth, intravenous fluids and systemic antibiotic therapy. He completed a 10-day course of antibiotics at home. A CT abdomen 2 months later showed complete resolution of the pneumoperitoneum (Figure 3). DISCUSSION: Prompt diagnosis of pneumoperitoneum and its cause is crucial, and it may require timely surgical intervention. However, there are causes of pneumoperitoneum that do not require surgery; these cases must be readily distinguished. One of the etiologies of asymptomatic pneumoperitoneum is rupture of the sub-serosal cysts present in the colonic wall of patients with idiopathic pneumatosis cystoides intestinalis. Primary pneumatosis intestinalis (15% of cases) is a benign idiopathic condition in which thin-walled cysts develop in the submucosa or subserosa of the colon. The secondary form (85% of cases) is associated with obstructive pulmonary disease, as well as with obstructive and necrotic gastrointestinal disease, infection, inflammatory bowel disease, medication-induced (chemotherapy and steroid), autoimmune disease, immunosuppression, and connective tissue disorders. In conclusion, intraperitoneal air is not always related to life-threatening conditions e.g. visceral perforation requiring invasive interventions; sometimes it is related to benign causes, one of them which we mentioned in our case. Therefore, the correlation should be made with the clinical presentation, frequent abdominal exams, imaging findings, and laboratory tests to prevent unnecessary interventions.