These lesions may be in the liver or the bile ducts leaving the liver. They are more common in women and usually occur after age 40. The most common symptom is right upper quadrant pain or fullness, but occasionally bile duct obstruction can occur. The lesions occur more commonly in the right lobe of the liver, but can occur anywhere. The size of the lesion can range from 1.5 to 15 cm, and are filled with fluid that may be composed of bile and cholesterol, even with crystals. The best treatment for these benign lesions is to resect them with surgery, since they can become malignant. They usually do not recur.