Is It Normal to Have Small Cysts on Your Liver on CT?
Yes, small simple hepatic cysts are extremely common and completely normal findings on CT scans, occurring in 15-18% of the general population, and they require no treatment or follow-up when asymptomatic. 1, 2
Prevalence and Natural History
Simple hepatic cysts are benign congenital lesions that arise from aberrant bile duct cells during embryonic development. 3 They are discovered incidentally with increasing frequency due to widespread use of abdominal imaging. 3, 4 The key point is that these cysts typically follow an indolent course without significant size changes over time—most (>80%) remain stable, some decrease in size, and only a minority grow modestly. 5
When Small Cysts Are Normal vs. Concerning
Simple cysts have characteristic imaging features that confirm their benign nature:
- Thin, smooth walls 3
- Homogenous low-density interior on CT 1
- No internal septations, calcifications, or solid components 3, 2
- No enhancement after contrast administration 1
Red flags that warrant further evaluation include:
- Irregular or thick walls 3
- Internal septations 3, 2
- Calcifications 3
- Mural nodules or solid components 1
- Daughter cysts (suggesting echinococcal disease) 3
Management Algorithm
For asymptomatic simple hepatic cysts (the vast majority):
- No follow-up imaging is recommended, regardless of cyst size 1, 6, 5
- Patient reassurance is the cornerstone of management 5
- The European Association for the Study of the Liver provides a strong recommendation (96% consensus) against routine surveillance 1, 6
If symptoms develop (abdominal pain, distension, early satiety):
- Ultrasound should be the first diagnostic modality to assess cyst size and complications 1, 6, 5
- Treatment success is defined by symptom relief, not volume reduction 6, 7, 5
- Laparoscopic fenestration is the preferred treatment for symptomatic cysts 7, 3
Common Pitfalls to Avoid
Overdiagnosis and unnecessary intervention: Radiologists sometimes include "rule out biliary cystadenoma" in their differential diagnosis for simple cysts, which can lead to unnecessary anxiety and surgery in asymptomatic patients. 8 A retrospective study found that 75% of asymptomatic patients diagnosed radiologically as cystadenoma actually had simple cysts on pathology, and 20% of patients underwent unnecessary surgery based solely on radiologic interpretation. 8
Unnecessary follow-up imaging: Routine surveillance of asymptomatic simple cysts increases healthcare costs and patient anxiety without clinical benefit. 5 Post-treatment imaging is also not indicated, as treatment success is measured by symptom relief rather than cyst size reduction. 1, 7, 5
Special Cyst Types That May Appear Small
While simple cysts are most common, other benign cystic lesions can appear small on CT:
- Biliary hamartomas: Multiple small (2-10 mm) lesions creating a "starry sky" appearance on MRI, requiring no follow-up 1, 6
- Peribiliary cysts: Small (<1 cm) cysts in perihilar distribution, often associated with portal hypertension and cirrhosis, also requiring no follow-up 1, 6
Both of these entities are benign and do not require surveillance. 1, 6