LAUSR

was required. The presumed pathogenesis of PI consists of several mechanisms: • Systemic infection leading to bacterial gas pockets within intestinal mucosa/submucosa • Mucosal disruption of any cause leading to mural penetration of bacteria or air (e.g. intestinal ischaemia) • Increased mechanical pressure within intestinal lumen (due to trauma, distension or iatrogenic inflation) • Immunosuppression from steroid/chemotherapy causing shrinkage of Peyer’s patches resulting in loss of the structural integrity of intestinal mucosa. In this case, the aetiology is not definite, as the PI occurred 2 years post-cessation of chemotherapy. According to literature, PI caused by chemotherapy spontaneously resolves shortly after chemotherapy is ceased. The surgeon must be familiar with benign aetiologies of PI to avoid unnecessary operative intervention. EUS can further characterize lesions found on endoscopy and differentiate benign pneumatosis coli from other differentials such as lymphoma which may guide the decision to obtain tissue biopsy. References