Liver cysts are thin-walled sacs filled with fluids, or semi-solid material. Liver cysts occur in approximately 5% of people. Cystic lesions of the liver represent a heterogeneous group of disorders, which differ in etiology, prevalence, and clinical manifestations. Most liver cysts are found incidentally on imaging studies and tend to have a benign course. A minority can cause symptoms, and rarely may be associated with serious morbidity and mortality. Larger cysts are more likely to be symptomatic and cause complications such as spontaneous hemorrhage, rupture into the peritoneal cavity or bile duct, infection, and compression of the biliary tree. Specific types of cysts may have unique complications such as malignant transformation in case of a cyst adenoma, or anaphylactic shock due to a hydatid cyst. The majority of cysts are benign, but may be cancerous. Liver cysts rarely impair the liver function.
Most liver cysts do not cause symptoms. Symptoms include: Upper abdominal fullness, discomfort or pain. Bleeding into the cyst, infection and rupture may cause sudden and severe upper abdominal pain radiating to shoulder . Cysts are diagnosed by ultrasound, CT scan and blood test .
Liver cysts with symptoms require treatment, which consists of surgically removing a large portion of the cyst wall ( Partial excision of cyst, marsupialization and omentoplasty),complete excision and hepatic resection in certain conditions . Only removing fluid from the cyst by aspiration is ineffective because it will form and fill up again within days.
Simple cysts of the liver are cysts containing clear fluid that do not communicate with the intrahepatic biliary tree. Simple cysts are found in approximately 1% of adults. Few cysts become large and cause symptoms.
Simple cysts tend to occur more commonly in the right lobe, and are more prevalent in women. The female-to-male ratio is approximately 1.5:1.
Symptomatic patients may present with abdominal discomfort, pain, or nausea. As a general rule, cysts in symptomatic patients are larger than those in asymptomatic ones . Large cysts can produce atrophy of the adjacent hepatic tissue while huge cysts can cause complete atrophy of a hepatic lobe with compensatory hypertrophy of the other lobe. Complications (such as spontaneous hemorrhage, bacterial infection, rupture or biliary obstruction) are more common in large cysts .
Polycystic Liver Disease (PLD):
Polycystic liver (PLD) disease is rare, affecting 6 out of 1,000 people. Liver cysts present as small or large grape-like clusters or a mixture of both. PLD is congenital and very often develops along with autosomal dominant polycystic kidney disease .
When the liver become massively enlarged and presses against nearby organs, surgery is then required to open or remove the cysts by hepatic resection. In extreme cases of PLD, liver transplantation is the only curative therapeutic option .Transplantation is indicated in those patients with extremely disabling symptoms that lead to a seriously decreased quality of life. In addition, untreatable complications, such as portal hypertension and nutritional compromise, are indications for liver transplant.
Cystic tumors are abnormal masses that have the potential to become malignant. Benign cystic tumors are called cystadenomas; their malignant counterparts are called cystadenocarcinomas.
Symptoms of cystic tumors include abdominal fullness and pain. Ultrasound and CT scans are used to diagnose cystic tumors, which have both liquid and solid components. Because of their malignant potential, all cystic tumors should be surgically removed.