Abstract
Activated pancreatic enzymes due to pancreatitis track along anatomic fascial planes and result in digestion of the surrounding tissues and pseudocyst formation. Pancreatic pseudocysts can cause variable complications in some cases. Abdominal contrast-enhanced CT scan can provide a valuable method to identify pancreatic pseudocyst and its related complications, especially in evaluating the adjacent vascular involvement. Splenic arterial pseudoaneurysm ruptured into pancreatic pseudocyst together with fistulous communication with the colon is a very rare condition. So, here we report such an additional case with abruptly acute lower gastrointestinal bleeding on his admission, who was finally diagnosed to be splenic arterial pseudoaneurysm ruptured into pancreatic pseudocyst coexisting with fistula to the colon by contrast-enhanced CT scan and treated successfully by urgent surgery.