What could a cyst on my liver be?

Likely nothing: Most liver cysts are harmless and do not need to be treated. Liver cysts can be present at birth or can develop at a later time. They usually grow slowly and are not detected until adulthood. Some cysts are caused by a parasite, echinococcus that is found in sheep in different parts of the world. Source: http://www.Liverfoundation.Org/abouttheliver/info/livercysts/.

Depends...: Anything from a simple, benign cyst to a more complex one. Your doctor can tell you which; and prescribe adequate follow ups to make sure there is no progression.

Red &'yellow: Simple small cysts in the liver, pancreas, kidneys o lungs are common and present no clinical significance. If you lived in south america or any region were schistosomiasis is prevalent ( red or yellow areas of map) your drs should rule it out.

Consider: ... Further assessment. Or followup while most are benign, monitor them for changes. Some are due to, or worsened by use of hormones. If you are on hormone treatment discuss this with your doctor. Large cysts can rupture and be life threatening.

Simple or biliary: Cysts in the liver fall into two categories: 1) simple cysts are congenital, can grow as the liver grows during childhood but are not likely to be symptomatic, 2) biliary cysts are also most likely congenital, but due to small connections with the bile ducts can slowly grow over time and become symptomatic. There is also the risk of cancer developing in biliary cysts.