Abstract
Cystic echinococcosis (CE) is a widely endemic helminthic disease caused by infection with metacestodes (larval stage) of the Echinococcus granulosus tapeworm and transmitted by dogs. E. granulosus are common parasites in certain parts of the world, and are present on every continent with the exception of Antarctica. As a result, a large number of people are affected by CE. In humans, the disease is characterized by slowly growing cyst commonly occurring in liver and lungs. Clinical features are mainly right upper quadrant pain, feeling of lump and enlarged tender liver. The cyst may be complicated by infection or rupture and may lead to anaphylactic reaction. The diagnosis depends on clinical suspicion. They appear in two ways as general (systemic) symptoms, and local symptoms based on the site and organ on which the larva settles. While cysts sometimes recover spontaneously, more severe clinical presentations are observed in immunosuppressed individuals. Ultrasonography supported by serology is the main diagnostic modality. The treatment varies from surgical intervention to minimally invasive treatments (percutaneous drainage) or medical therapies. Surgery is still the best treatment modality. Percutaneous drainage of the cyst is a good option in selected cases. New sensitive and specific diagnostic methods and effective therapeutic approaches against echinococcosis have been developed in the last 10 years.
Echinococcal cysts, although fairly uncommon, should be considered in the differential diagnosis of hepatic cysts.
Serum antibody assays generally have low sensitivities, but antigen assays may be of value.
Imaging is crucial in determining cyst stage, size, location and complications.
Uncomplicated active cysts can be managed with chemotherapy alone or in combination with a PAIR approach. Inactive cysts can be managed with the “watch-and-wait” strategy.
Surgery is the first choice when there is cystobiliary fistula and significant extra-hepatic extension with high risk of perforation.
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