When Pancreatitis Strikes the Colon: A Rare Case Report of Sigmoid Perforation.

Introduction: Acute pancreatitis is a potentially severe condition that can lead to both local and systemic complications. Colonic complications are uncommon but include fistula formation and perforation, both of which are associated with high morbidity and mortality. This is a case of colon perforation in an unusual location, following an episode of acute pancreatitis. Case Presentation: We report the case of a 75-year-old man with a history of arterial hypertension, dyslipidemia, and atrial fibrillation on direct oral anticoagulation who presented with sudden upper abdominal pain and vomiting. Abdominal ultrasound showed no evidence of gallstones or biliary obstruction. The patient reported a daily alcohol intake of approximately 50 g, and laboratory tests revealed markedly elevated amylase and lipase levels. On admission, the patient was hemodynamically stable, with no evidence of organ failure. A diagnosis of mild acute pancreatitis with uncertain etiology was made. Initially stable, the patient developed new-onset abdominal pain and signs of peritonitis on the fifth day of hospitalization. CT revealed pneumoperitoneum and a retroperitoneal hematoma. Exploratory laparotomy confirmed sigmoid colon perforation, and a segmental colectomy with end colostomy was performed. Histopathological examination of the resected sigmoid colon excluded the presence of diverticula or neoplastic lesions and revealed inflammation of the subserosa and serosa adjacent to the perforation. Case Discussion: Colonic perforation secondary to acute pancreatitis is exceedingly rare, and its pathophysiology is not fully understood. The leading hypothesis suggests the spread of activated pancreatic enzymes through the mesocolon, leading to pericolitis, ischemia, and transmural necrosis. Most reported cases involve the transverse or descending colon, but sigmoid involvement, as in this case, underscores the unpredictable nature of this complication. Conclusion: This case highlights a rare but severe complication of acute pancreatitis. Clinicians should consider colonic involvement in patients with unexplained clinical deterioration. Early recognition and prompt surgical intervention remain key to favorable outcomes.