Wenn die Leber zu groß ist - Diagnose

Hydatid liver disease results from infection by tapeworm larvae of the genus Echinococcus. There are four main types: for E granulosus the definitive host is the dog: for E multilocularis the definitive host is the fox; for E vogeli the definitive host is the bush dog (found commonly in South and Central America);² and for E oligarthrus felids (carnivorous mammals, including the domesticated cat and big cats such as lions, tigers, panthers, lynxes, leopards, pumas, and cheetahs) are the definitive hosts.³

As well as the definitive hosts, the life cycle of tapeworm requires intermediate hosts: humans, sheep, goats, swine, cattle, horses, camels, and rodents. The adult tapeworm (E granulosus) infects the intestinal tract of the definitive host; it produces eggs, which are expelled within the host’s faeces. The intermediate host ingests the cyst-containing organs of the infected host. The eggs hatch, and the tiny embryos travel in the bloodstream and lodge in organs such as the brain, liver, spleen, lungs, and kidneys; these form hydatid cysts.⁴

Hydatid disease is found mainly in sheep farming areas, notably in Greece and Turkey, and 10-20 cases are reported in the UK each year. Prevention is targeted at deworming dogs that might be carrying this parasite, as well as good hygiene after contact with dogs and sheep.

Treatment
The mainstay of treatment is prevention of cyst rupture, which could cause anaphylaxis. This is done with albendazole to reduce the size of the cyst. Albendazole acts to reduce glucose uptake by the tapeworm microtubules and causes the tapeworm to die. Praziquantil reduces contamination of the peritoneal cavity by increasing permeability of the parasite cells to calcium, thereby inducing contraction and paralysis of the parasite cells.⁵ This initial medical management sterilises the cyst, reduces the cyst wall tension, which is important intraoperatively, and reduces recurrence.⁶ Subsequent surgical management involves removal of the cysts without rupturing or puncturing them, guided by computed tomography; aspiration of fluid; and injection of hypertonic saline solution as a scolicidal agent.⁴ In cases of recurrent cysts, liver resection may be needed.⁷

Cite this as: BMJ 2008;337:a3090