Improvements in radiographic imaging over the last several decades have led to an increased recognition of cystic lesions in the liver and biliary tract. These cysts have a wide range of etiologies including congenital malformations, infections, and neoplasms. This chapter discusses benign, infectious, and neoplastic cysts of the liver and biliary tract. A complete understanding of the presentation, risk factors, and radiologic features is crucial to accurately identifying these cysts. Accurate identification is essential for determining the best treatment strategy, which may require surgery.
Simple cysts of the liver are spherical or ovoid cystic formations without septations containing serous fluid which are lined by a single layer of biliary columnar or cuboid epithelial cells. These cysts are congenital, having originated from aberrant bile ducts that have lost communication with the biliary tree and as a result have no direct communication with the bile ducts.1 Despite a biliary origin, these cysts rarely contain bile. The majority of patients will have a solitary cyst, although multiple cysts can be seen. The cells lining the cyst continue to secrete serous intraluminal fluid and as a result the cyst may gradually increase in size, although few will grow large enough to be symptomatic (Fig. 137-1). While most are less than 3 cm, rare hepatic cysts have been reported over 20 cm in diameter.2 Simple cysts can be found in any part of the liver but are more commonly located in the right lobe (Fig. 137-2).3
CT imaging of a 71-year-old patient presenting with a simple liver cyst 3.3 × 5.8 cm in 2008 (A) and increasing to 7.7 × 10.1 cm in 2014 (B).
CT imaging of a 62-year-old female presenting with a 15 × 15 × 19 cm simple hepatic cyst of the right lobe of the liver.
Noninfectious simple liver cysts are a frequent incidental finding in asymptomatic adults undergoing workup by ultrasound or computed tomography (CT) for other purposes. Simple hepatic cysts have been reported in 2.5% to 18% of adult patients without prior liver disease who have undergone abdominal imaging by ultrasound, CT, or magnetic resonance imaging (MRI).3-5 Cysts are more prevalent in older females; large, symptomatic cysts are found almost exclusively in females.3 While most patients with simple cysts are asymptomatic, symptoms may occur due to enlargement, mass effect, infection, hemorrhage, or rupture of the cyst. Patients with simple cysts may present with abdominal discomfort, pain, nausea, or early satiety often related to the size or location of the cyst. Simple cysts greater than 4 cm in diameter and those located in the right lobe ...