There is a very special category of mediastinal tumors, why “they”? Because they are made of water, just like women, and our doctors like to call them mediastinal cysts. They are a group of people who are divided into: tracheobronchial cysts, esophageal cysts, gastrointestinal cysts, pericardial cysts, and thymic cysts depending on the place of origin. Most of them are born with congenital diseases and grow up slowly during the process of human growth and development. Because they are gentle and quiet, they do not cause significant discomfort and pain to most patients, even if they exist in the mediastinum for a long time. Therefore, most patients find mediastinal cysts in their mediastinum often as a result of a chest CT physical examination, which will show them to be uniform and relatively low density, suggesting that they are mainly composed of water. However, some patients have discomfort because they (cysts) are so fat that they squeeze into the normal tissues and organs in the mediastinum, affecting the function of normal tissues and organs, such as: breathing difficulty, asthma and cough when they squeeze into the trachea; difficulty in swallowing when they squeeze into the esophagus; chest tightness and chest pain when they squeeze into the heart vessels, etc. Due to the improvement of health awareness, more and more people are having medical checkups, and mediastinal cysts are gradually found more and more. Well, to cut or not to cut, that is the question. Probably because most of the thoracic surgeons are male, they inevitably have some compassion for “them” and often tell patients with small, asymptomatic cysts not to cut them for the time being, but to follow up with annual chest CT, and to come back for surgery when they grow up or have symptoms (the fact is that chest surgery is bound to bring some trauma to the patient, even if the chest surgery has already been done). (The fact is that chest surgery is bound to bring some trauma to the patient, and even though chest surgery has entered the era of minimally invasive surgery, some patients will still have some discomfort after surgery, so surgery has risks and admission needs to be cautious.) If the cyst is already large, and further growth will increase the difficulty and risk of surgery, or if the cyst has already produced adverse consequences, or if the patient has the above mentioned discomfort, or if the cyst cannot be diagnosed and the patient has greater psychological pressure, the patient is recommended to undergo surgery. Thoracic surgery has entered the era of precise, minimally invasive and rapid recovery, and thoracoscopic surgery or da Vinci robotic surgery will be a good choice, and most patients can be discharged from the hospital quickly after surgery. Of course, since mediastinal cysts are a group of diseases, each disease and each patient is bound to have some minor differences. In this article, we hope to give the general public some basic medical knowledge about mediastinal cysts and to look at them with a calm and rational mind, but the specific diagnosis of the disease and the determination of the treatment plan need the help of a professional thoracic surgeon.