Hepatic Cysts

Hepatic Cysts can be divided into nonparasitic cysts and echinococcal cysts.

A. Nonparasitic cysts

Nonparasitic cysts generally are benign. They can be solitary or multiple and often are identified incidentally on imaging for other symptoms.

Asymptomatic cysts require no treatment regardless of size. Large cysts may be symptomatic because of increased abdominal girth or compression of adjacent structures. Bleeding, infection, or obstructive jaundice can occur but are infrequent.

Symptomatic cysts can be unroofed operatively by either an open approach or, more recently, by laparoscopy. Infected cysts are treated in a similar manner to hepatic abscesses. If the cyst contains bile, communication with the biliary tree is assumed. It should be excised, enucleated, or drained, with closure of the biliary communication.

Polycystic kidney disease sometimes is accompanied by polycystic liver disease, which usually is asymptomatic. Symptoms generally are attributable to hepatomegaly from numerous cysts. Liver function is rarely impaired by the gross displacement of parenchyma by these massive cystic cavities. Symptomatic polycystic liver disease has been treated by drainage of the superficial cysts into the abdominal cavity and fenestration of deeper cysts into the superficial cyst cavities. Liver resection and retention of the least-cystic areas of hepatic parenchyma may be more effective. Neoplastic cystic lesions such as cystadenoma or cystadenocarcinoma rarely occur in the liver. These lesions are distinguished from simple cysts by the presence of a mass or septa. They are treated by resection or enucleation (in the case of cystadenoma) to completely remove cyst epithelium.

B. Echinococcal cysts

Echinococcal cysts are the most common hepatic cystic lesions in areas outside the United States. Approximately 80% of hydatid cysts are single and in the right liver.

The most common presenting symptoms and signs are right-upper-quadrant abdominal pain and palpable hepatomegaly.

Imaging by nuclear medicine scan, ultrasonography, CT scan, or MR scan can demonstrate the abnormality. The cyst should not be aspirated as an initial test because aspiration can cause spillage of theorganisms and spread the disease throughout the abdominal compartment. A peripheral eosinophilia is often detected. Serologic tests include indirect hemagglutination and Casoni skin test, each of which is 85% sensitive.

Treatment is primarily operative, although percutaneous drainage after antihelminthic treatment is increasingly utilized in many centers in endemic regions. The abdomen is explored, and before unroofing, the cyst cavity is aspirated with a closed system. If there is no evidence of bile in the cyst aspirate, a scolecidal agent is instilled into the cavity. Choices include hypertonic saline, 80% alcohol, or 0.5% cetrimide. A second cycle is performed after 5 minutes. In patients with biliary communication, only hypertonic sodium chloride (10% to 20%) or 0.5% sodium hypochlorite should be used as a scolecidal agent because other agents may damage communicating bile ducts. Pericystectomy is excision of the cyst in the plane between the host pericyst and liver tissue. The advantage of this technique is that there is no residual cavity. Formal hepatectomy is rarely necessary except for large and/or multiple cysts. For those cysts with demonstrated communication with a biliary radical, drainage should be achieved with a Roux-en-Y hepaticoenterostomy. Postoperative therapy with mebendazole or albendazole has been advocated to prevent recurrence.