What is a Hydatid Cyst?

A hydatid cyst is a pocket inside the body filled with larval forms of Echinococcus worms. The cyst poses a threat to health in the host organism in a number of ways and typically needs to be removed surgically and treated with chemotherapy if it is identified before it ruptures. In cases where cysts have ruptured, treatment options vary, depending on the location of the cyst and the damage caused by the rupture. People develop cysts as a result of consuming eggs in contaminated food and water.

Depending on the worm species involved, sometimes a single large cyst will form, and in other cases, a patient will have a plethora of small cysts. A hydatid cyst forms when eggs hatch into larvae and the larvae burrow through the intestines, drifting through the body until they find a hospitable location to encyst. The cyst may form in or around the lungs, heart, liver, or kidneys. Over time, it will fill with fluid and develop a tough wall.

A person can carry a hydatid cyst for months or years without being aware of it. Often, the first signs of its presence are indicators of obstruction caused by the cyst, such as jaundice in a person with a liver cyst, or loss of vision in someone with a cyst near the optic nerve. Medical imaging studies will reveal the presence of a cyst and a patient interview can suggest exposure to Echinococcus worms, most commonly as a result of traveling in an area where the worms are endemic.

In treatment, the cyst will be taken out in a surgical procedure. The goal is to remove the cyst in entirety and to avoid rupturing it during surgery while also taking care around delicate anatomical structures in the surrounding area. This can require a high level of skill, especially with cysts in locations like the brain, where the surgeon needs to extract the hydatid cyst with minimal damage. Once the cyst is removed, the patient can be given medications to reduce the risk of infection and kill any lingering organisms that might be left in the body.

When a cyst ruptures, the body is flooded with organisms that will latch onto the intestines and mature into adults. Infections with adult organisms can result in malnutrition, as well as gastrointestinal distress. The patient can also be at risk of secondary infections and other health problems when a hydatid cyst breaks open, and it is important to receive a thorough medical evaluation.