Congenital non-parasitic hepatic cyst complicated by hepatoduodenal fistula: a rare case report

Introduction and importance: Simple hepatic cysts are benign and usually asymptomatic; however, they can rarely develop serious complications, such as hepatoduodenal fistula, due to infection, cyst size, or mechanical pressure. Case presentation: A 68-year-old male presented with fever, hematochezia, and severe right upper quadrant pain. Imaging revealed a 10 × 12 cm segment V–VII hepatic cyst with an air–fluid level, and endoscopy showed a fistulous opening in the second duodenum adjacent to a necrotic diverticulum. After stabilization, laparotomy confirmed a hepatoduodenal fistula; a 2 cm opening was closed with an omental patch, the cyst was deroofed, and a drain was placed, resulting in excellent recovery. Clinical discussion: This rare hepatoduodenal fistula arose from an infected simple hepatic cyst (pathology: cuboidal epithelium; negative Echinococcus serology), driven by inflammation and mechanical stress. Percutaneous drainage failed due to enteric communication; surgery was definitive. Conclusion: Infected simple hepatic cysts can rarely progress to a hepatoduodenal fistula with significant morbidity, but prompt diagnosis, resuscitation, antibiotics, and definitive surgical repair can result in full recovery.