Marrero JA, Ahn J, Rajender Reddy K, American College of Gastroenterology. ACG clinical guideline: the diagnosis and management of focal liver lesions. Am J Gastroenterol. 2014 Sep;109(9):1328-47; quiz 1348. doi: 10.1038/ajg.2014.213. Epub 2014 Aug 19. PMID: 25135008.
Parasitic cysts of the liver are mainly echinococcal cysts due to infection caused by 1 of 2 species of Echinococcus: E granulosus (cystic echinococcosis) or E multilocularis (alveolar echinococcosis).
Clinical features: Manifestations occur in a varying proportion (up to 80%) of the infected individuals and depend on the location of the cysts, their size, the degree of development and viability of the parasite, and occurrence of complications. In most cases (>80%) echinococcosis manifests as a single cyst located in the liver, most frequently in the right lobe. In the case of alveolar echinococcosis, apart from the primary cyst located in the liver, in ~30% of patients extrahepatic lesions develop as a consequence of infiltration or dissemination to distant sites.
Diagnosis: Imaging findings raise suspicion: see Table 7.3-1; the etiologic factor should be identified.
Treatment: Surgical removal of cysts is the treatment of choice, especially in alveolar echinococcosis. Liver resection or cystopericystectomy (excision of a cyst without opening the lumen) is performed. In echinococcosis, transdermal therapy in specialist centers is also acceptable. Liver transplant can be performed in patients with alveolar echinococcosis who have very advanced multifocal lesions within the liver parenchyma, a priori unresectable, or in whom disease progression has led to liver failure.