Biliary cystadenoma

Biliary cystadenomas, also known as mucinous cystic neoplasms of the liver, are uncommon benign cystic neoplasms of the liver.

Epidemiology

Biliary cystadenomas occur predominantly in middle-aged patients and are more common in women ¹.

Clinical presentation

The clinical presentation of biliary cystadenomas is variable, depending on the size and location of the tumor. Symptoms and signs may include ¹:

• right upper quadrant pain

• obstructive jaundice

• palpable liver edge or mass

• increasing abdominal girth (large tumors)

• nausea and vomiting

Pathology

Biliary cystadenomas are cystic neoplasms that may be either unilocular or multilocular. Only rarely are they found in the extrahepatic biliary tree and gallbladder.

The criteria for cystadenomas include ^1,6:

• cysts lined by cuboidal or columnar epithelium that resembles normal biliary epithelium

• usually no communication with the bile ducts

• variable amount of mucin-producing epithelium

• associated with ovarian-type subepithelial stroma

Radiographic features

Biliary cystadenomas range in size from 3 to 40 cm and can be either unilocular or multilocular. Unfortunately, there are no specific imaging features that permit reliable differentiation of biliary cystadenoma from biliary cystadenocarcinoma.

Ultrasound

A biliary cystadenoma appears as a unilocular or multilocular cyst with enhanced through transmission. The content of the cysts may range from completely anechoic to having low-level echoes from blood products, mucin, or proteinaceous fluid.

Mural nodules and papillary projections may project into the cyst lumen. If septal or wall calcification is present then acoustic shadowing may be seen.

CT

As is the case with ultrasound, the appearance of the cyst fluid on CT is variable depending on its composition. It can range from that of water (0 HU) to quite hyperattenuating if the cyst has been complicated by recent hemorrhage.

Calcifications of septa or cyst wall may be seen. Additionally, the septa may enhance following administration of contrast.

Focal upstream bile duct dilatation and perilesional THAD are described features associated with cystadenomas due to their mass effect over the bile ducts and portal venous flow (cf. hepatic cysts) ⁵. 

MRI

The MR signal intensity of biliary cystadenoma is variable on both T1- and T2-weighted images, depending on the content of the cyst fluid.

Treatment and prognosis

Although biliary cystadenomas are benign tumors, they may recur after excision and have the potential for malignant degeneration into biliary cystadenocarcinomas.

Differential diagnosis

General imaging differential considerations include other cystic liver lesions, including:

• hepatic cyst

• biliary cystadenocarcinoma

• hepatic lymphangioma

• IPMN of the bile ducts

• hydatid disease of the liver

• hepatic abscess

• hepatic tuberculosis ⁴