A Case of Echinococcosis: Surgical Management of Hepatic Hydatid Cyst

Abstract

Echinococcosis is a parasitic infection, also known as hydatidosis, caused by of the tapeworm Echinococcus. In regions endemic to cystic echinococcosis the World Health Organization reports incidence rates over 50 per 100,000 person-years. It is globally distributed and commonly seen in regions with pastoral and rangeland areas. Humans are accidental intermediate hosts through ingesting food and water contaminated with the parasites eggs. The species Echinococcus granulosus causes cystic echinococcosis predominately affecting the liver. A 34 year old female Yemeni immigrant, presented with the chief complaint of right upper quadrant abdominal pain, and slightly elevated transaminases. An abdominal CT with contrast noted a 10.1 X 9.3 cm cyst in the superior right hepatic lobe. Using ultrasound guidance cyst 500 ml of colorless fluid was aspirated from the cyst. Cytology demonstrated parasitic structures with hooklets consistent with Echinococcus. She was treated with a 10 day course of Albendazole, however she continued to have persistent abdominal pain. Repeat CT and US revealed recurrence of the cyst with findings concerning for daughter cyst formation. Based on World Health Organization staging criteria treatment options included; repeat cyst aspiration or surgical resection with concomitant Albendazole. In light of the cystic septations noted on MRI surgery was favored and she underwent hepatic segment VII resection with the encapsulated cyst. She had an uneventful recovery with normal hepatic function and was discharged home with 4 weeks of albendazole therapy. Repeat ultrasound 2 months post op revealed no evidence of recurrent cyst formation. The diagnosis of hepatic hydatid cysts requires a high degree of clinical suspicion and knowledge of the subtle signs and symptoms of the disease. Early diagnosis and appropriate treatment prevents complications of the disease including pressure symptoms, cyst leakage, cholangitis and anaphylaxis. Treatment options are dependent on the stage of the hydatid cysts, and surgery should be considered for patients who have not responded to medical management and have evidence of cyst criteria not amenable to percutaneous drainage. Rates of recurrent infection are significantly lower after radical surgical procedures however follow up is still recommended for up to 5 years post treatment with periodic imaging.Figure: Cut sections of the single hepatic cyst with multiple concentric membranes and yellow scoleces.Figure: Admission CT abdomen and pelvis with contrast shows right hepatic lobe cyst measuring 10.1 x 9.3 cm.Figure: MRI w contrast demonstrating the floating membranes.