With the widespread use of liver imaging (ultrasound, CT, etc.), many people find out they have liver cysts during medical examinations. Some patients are a little nervous when they see the diagnosis of liver cysts and are eager to get guidance and help from their doctors. What kind of disease is a liver cyst anyway? Is it a tumor? Does it matter? How to deal with it? 1.Liver cyst is a common disease It can be said that liver cyst is one of the most common benign diseases of liver, accounting for 1%-2% of physical examiners. In the past, liver cysts were thought to be congenital, but in fact, there are congenital and acquired liver cysts. Congenital liver cysts are caused by abnormal development of intrahepatic bile ducts or lymphatic vessels during embryonic period. However, there are some people who have never found liver cysts during years of physical examination, and as they grow older, newborn cysts appear in the liver, which can be called acquired liver cysts. Acquired liver cysts may be the result of degenerative changes in the liver ducts. Liver cysts are usually spherical in shape, with a fibrous outer shell that is filled with clear, colorless or egg-yellow cystic fluid without cellular components. Most liver cysts are very small, 1-2 cm in diameter, resembling the size of a grape, but some can grow to be very large, up to 10-20 cm or more in diameter. Liver cysts can be single or multiple, mostly scattered in the liver. There is no certain pattern of growth of liver cysts and they can grow in any part of the liver. In general, liver cysts do not rupture, bleed, infect, or become malignant. However, in a few patients, intracapsular hemorrhage may occur, resulting in a bloody cystic fluid or blood clots. Sometimes infection can develop secondary to the cyst. Most liver cysts do not grow or grow slowly, and giant liver cysts are relatively rare. Most liver cysts are asymptomatic and are often detected during physical examination. However, some patients experience abdominal discomfort or pain, which may be due to the superficial location of the cyst and its tendency to rub against the diaphragm or peritoneum. Huge liver cysts can also squeeze the surrounding organs, making the patient feel abdominal discomfort or fullness, even affecting digestion and breathing. 2, liver cysts are not difficult to diagnose liver cysts mainly rely on imaging examinations for diagnosis. Among them, ultrasound examination is the most commonly used and the method is simple. However, CT examination is obviously better than B ultrasound in guiding the surgery when it comes to a comprehensive understanding of the size, number and location of cysts as well as the liver and related organs around the liver, especially for patients with larger liver cysts that need to be treated. Usually, liver cysts do not cause abnormalities in liver function and no laboratory tests are needed. However, sometimes some blood tests are still necessary for differential diagnosis, especially the blood AFP test to exclude primary liver cancer. 3.What liver cysts need treatment Although liver cysts are benign tumors, treatment should be considered for the following types of liver cysts. (1) Oversized liver cysts A few liver cysts grow faster and when they exceed 5 cm in diameter, they can be called large liver cysts. Large liver cysts tend to cause compression symptoms and affect life and work. (2) Cyst secondary infection A few liver cysts can be secondary to infection, and these patients can have inflammatory manifestations such as pain in the liver area, fever, elevated blood leukocytes, and ultrasound examination suggesting cyst infection. These patients should not continue to be observed, but should be treated promptly. (3) Cyst secondary bleeding A few liver cysts may have spontaneous rupture of blood vessels in the cyst wall leading to intracapsular bleeding. Some patients do not have obvious symptoms, but some patients have severe pain in the liver area, cool like acute abdomen, such as conservative treatment without effect for treatment. 4.Treatment of liver cysts More than 10 years ago, most of the treatment of liver cysts used surgical methods, which are surgically traumatic, and since the interventional treatment method of percutaneous liver puncture is available, the surgical method has been basically not used. This interventional method is performed under ultrasound guidance, using a fine needle to aspirate the fluid from the cyst and then injecting a small amount of anhydrous alcohol to destroy the cells that secrete the cyst fluid and prevent recurrence. This method is simple and safe, and is also suitable for elderly and frail patients. For those with secondary infection, a drainage tube can be placed on top of the aspirated fluid and flushed with antibiotics, which will heal in a short time. For those with secondary bleeding, injection of a hemostatic agent into the cyst is sufficient.