Hepatobiliary and pancreatic: Biliary rupture of an hydatid cyst

Abstract

Hydatid cysts form when the larvae of Echinococcus granulosis encyst within the liver or other organs. Cysts often grow at a rate of approximately 1 cm per year but it is common for cysts to lose viability in patients over 60 years of age. The majority of human infections are asymptomatic. However, cysts that are 10 cm or more in diameter can cause discomfort or pain in the upper abdomen. The most common acute presentation is that of rupture of the cyst into the biliary system. This usually results in cholangitis with jaundice. Other acute presentations involve liver abscesses, pancreatitis and rupture of hepatic cysts into the peritoneal or pleural cavities. In the patient described below, the hepatic cyst ruptured into the left hepatic duct and resulted in cholangitis. A 54-year-old man was admitted to hospital with upper abdominal pain, jaundice and fever (39.6°C). Abdominal pain had been present for approximately 4 weeks and had been associated with anorexia and weight loss. On physical examination, he had an enlarged liver with upper abdominal tenderness. Blood tests revealed an elevated white cell count (19.4 × 109/l) with a high erythrocyte sedimentation rate (113 mm/h) and an elevated C-reactive protein (75 mg/l). The serum bilirubin was elevated at 323 µmol/l and this was associated with a high alkaline phosphatise (1143 U/L) and a minor elevation of aspartate aminotransferase (126 U/L) and alanine aminotransferase (109 U/L). An upper abdominal ultrasound study showed a cystic lesion in the left lobe of the liver with a dilated left hepatic duct. A contrast-enhanced computed tomography scan (Figure 1) showed a cystic structure in the left lobe of the liver, patchy calcification of the cyst wall, air in the right hepatic duct and mild dilatation of the bile duct (14 mm). No abnormalities were seen in the gallbladder. With magnetic resonance cholangiopancreatography (Figure 2), the irregular cystic structure communicated with the left hepatic duct. In addition, the bile duct was mildly dilated and the cystic structures and the bile duct were filled with spiral filling-defects. The patient was treated with antibiotics and subsequently had a surgical procedure that included a left hepatectomy, cholecystectomy, choledochotomy and T-tube drainage. On microscopic examination, there was hydatid sand with a protoscolex of E. granulosis. In the post-operative period, he was treated with albendazole. Endoscopic sphincterotomy was not performed in the above patient but can facilitate resolution of cholangitis.