According to breastcancer.org, about 25% of breast masses turn out to be cysts. Cysts are round or oval organic structures filled with fluid. Many people think we can feel all breast cysts through the skin. Although this is true of many cysts, some are so small they are only detected with diagnostic imaging. A cyst that you can feel OR seen through imaging is a “gross cyst.” Still, some cysts are so tiny that they are virtually undetectable until they grow.
