In recent years, the development of lumpectomy and minimally invasive surgery in various surgical specialties has become faster and faster, and in the foreseeable future, lumpectomy and minimally invasive surgery will definitely be a major trend of development. However, in the clinical work, especially in the preoperative conversation of tumor patients, there are often family members or patients who ask such questions: Can minimally invasive surgery for malignant tumors be clean? First of all, let’s talk about how to do tumor surgery? How can the tumor be considered clean? Let me make an analogy first. The human body is like a big tree, with branches, leaves and fruits. An organ is like a big branch of the tree, the leaves and fruits are like the soft tissues of the organ, then the branches are the blood vessels that supply the organ. A tumor in human body is equivalent to a mutated bad fruit growing on a branch, and this bad fruit can spread to other branches through the branch, that is, its blood vessels. Generally speaking, we have to remove the whole branch from its root to be considered “clean”. But it is too easy to say that cutting tumor is like sawing a branch. In fact, human organs, especially the blood vessels supplying them, are often buried in the surrounding tissues, and it requires certain techniques, skills and patience to remove them completely without hurting the surrounding tissues. Next, let’s be more specific, how can we achieve “complete excision”? We all know the story of Butcher, “He has between the joints, and the blade is not thick; with no thickness into the intervening, the recovery will be carried out in the free edge. There are potential gaps between different tissues, and a good surgeon can remove the organ where the tumor is located completely or partially along the tissue gap without touching the tumor, which is the principle of “no touching” for tumor resection, in order to prevent the spread of tumor cells caused by intraoperative extrusion. The identification of tissue gaps is a crucial skill in surgery, in which good vision and illumination can make the identification of tissue gaps relatively easy. In traditional surgery such as open surgery, the patient is lying on the operating table and the surgeon is standing up, the distance from the operating area to the surgeon’s eyes is at least one foot, so the ability to identify the fine structures is actually limited. In lumpectomy, a slender lens of more than one foot long is placed into the abdominal cavity through a small hole, and there is a good light source at the front of this lens, so the operator can identify the fine tissue structures at close range through the TV screen, which is equivalent to sticking the operator’s head into the abdominal cavity for observation. Some special parts of the surgery, such as the surgery of low rectal cancer, the rectum is surrounded by narrow bony structures, retraction is completely ineffective, open surgery can not talk about the good or bad surgical field. I remember when I followed my teacher in the rectal surgery, I pulled the hook hard and watched him put his hand in and gouge the tumor out, but those with bigger hands could not do the rectal surgery, and if they accidentally broke the presacral vessels, it would cause hemorrhage. Now we do rectal surgery through the lumpectomy, we can clearly see the gap free to the pelvic floor, the surrounding blood vessels and nerves are clear, really can achieve complete removal of the entire mesentery, this is really “cut clean”. Finally, let’s answer this question: Can minimally invasive surgery for malignant tumors be clean? Our answer is: it is cleaner than open surgery!