Liver Cyst
A liver cyst is a fluid-filled sac within the liver. Most liver cysts are simple, benign, and discovered incidentally during imaging done for unrelated reasons. They typically cause no symptoms and require no treatment unless they grow large or develop complications. Cysts may be present at birth or develop gradually over time.
What is it?
A liver cyst is a round or oval pocket of clear fluid within the liver. Simple cysts have thin, smooth walls and no internal structures, which is how radiologists distinguish them from more complex lesions. Most simple cysts are harmless and remain stable in size for years. Some cysts may develop from small bile duct irregularities or be present since birth.
Imaging helps confirm that the cyst is simple and benign. Ultrasound typically shows a smooth, fluid-filled structure, while CT or MRI can provide additional detail if the cyst has unusual features or is very large. Cysts that contain internal septations, thick walls, debris, or enhancement are classified as complex cysts and may require further evaluation.
Important to Know
Simple liver cysts do not increase the risk of liver cancer and rarely cause symptoms. Large cysts may cause fullness, pain, or discomfort, especially after eating. In rare cases, cysts can bleed, become infected, or twist, causing sudden pain.
Red flag symptoms include severe abdominal pain, fever, jaundice, or rapidly increasing abdominal fullness. These may indicate complications that require urgent evaluation. Follow-up imaging is rarely needed unless the cyst is large, atypical, or associated with symptoms.