Section: Hepatobiliary Sub-section: Liver Curriculum: Curriculum, page 85
Definition
- Membranous sac usually lined by bile-duct epithelium containing bile like fluid but with no communication to bile ducts.
Epidemiology
- Common
- Seen in 6% of ultrasounds.
- 50% of people >60y.
- Maybe more common in female.
- Symptomatic cysts 10 times more in female compared to male
Aetiology
- Simple cysts arise during embryogenesis when intrahepatic ductules fail to connect with intra- or extrahepatic ducts
Clinical
- Mostly incidental.
- Some experience abdominal pain, early satiety, nausea and vomiting due to mass effect.
- Exam may reveal palpable mass or hepatomegaly.
- Complications such as haemorrhage, rupture and biliary obstruction rare, more likely in larger cysts
Investigations
USS
- High sensitivity and specificity
- 90% for diagnosing cysts CT
- shows well demarcated, water-attenuated, smooth lesion without internal structure and no enhancement with contrast MRI
- Accuracy 97%.
Considerations
- Aspiration not needed for diagnosis
- If haemorrhage occurs, USS shows hyperechogenic pattern with septations or solid portions.
- If irregularities and nodules in cystic wall, should be considered neoplastic.
- Rarely have calcifications (more characteristic of hydatid)
Management
- Asymptomatic cysts do not require treatment
- Symptomatic may require intervention
- Percutaneous aspiration – not definitive as recurs but can clarify if abdominal pain related to cyst
- Percutaneous aspiration sclerotherapy – first line. Recurrence rate 20-30%
- Surgery:
- Indicated if:
- Biliary communication and infection
- Sclerotherapy ineffective
- Recurrence
- Deroofing or fenestration results in excellent reduction of symptoms.
- Recurrence rate 10-25%
- Excision not necessary and can result in additional morbidity as there is no dissection plane between cyst and crucial structures in liver
- If histology of cyst wall abnormal of indicative of Cystadenoma, hepatic resection indicated
- Indicated if: