Surely the endometrium should be growing inside the uterus? How can it “cross” into the knife? Don’t believe me, look at the following short story you can understand. Miss Zhao gave birth to a child by Caesarean section two years ago, the obstetrician was very careful, the location of the incision in the underwear, with the use of intradermal sutures, the wound and the skin pattern is consistent, a very thin line, do not look closely can not see, Miss Zhao was very satisfied. But after six months, Miss Zhao found a small hard knot under the skin in the incision, so that the opening of the obstetrician to see, the doctor felt that it may be the reaction of the following line knot, so let observe a period of time. But this indisputable little thing slowly grows, from the size of a red bean to the size of a jelly bean, and from time to time will hurt for several days, and when the pain will become larger. Obstetrician prescribed ultrasound, under the incision is a 2.5cm-sized nodule, rich blood supply, Miss Zhao looked at the report a little scared, guessing that it will not be a bad thing like a tumor. The obstetrician took Miss Zhao to the abdominal wall surgery, the abdominal wall surgeon conducted a physical examination and asked her a question: “Is the time of pain the period of menstruation? Is it true that the pain will get better when the period is over?” Ms. Zhao carefully recalled that this was indeed the case. The abdominal wall surgeon smiled and told her that the hard knot was an ectopic endometrium, not a bad problem. Miss Zhao’s first reaction was the question at the beginning of this article, how did the endometrium cross into the incision? The doctor told her the reason, endometriosis is actually a common gynecological disease, many women’s menstrual pain is the culprit. This is because under normal circumstances, the endometrium and menstrual blood shed during menstruation is discharged downward, but sometimes there is a small amount of reverse ectopic through the fallopian tube to the abdominal pelvic cavity, and a small number of planted live; after moving the endometrium will thicken with the menstrual cycle and partly shed and bleed as normal endometrium, which leads to dysmenorrhea because there is no normal discharge channel. For those who have had a cesarean section like Zhao Xiaojie, some of the endometrium is brought into the incision when the uterus is cut open to remove the fetus, which happens to survive and becomes endometriosis in the abdominal wall. The ectopic endometrium changes with the menstrual cycle, so there will be periodic pain and size changes, and because the ectopic endometrium bleeding can not be discharged and eventually mechanized, so it will form larger and larger hard nodes, which led to Ms. Zhao’s condition. Endometriosis of the abdominal wall is uncommon and by no means rare, and can be diagnosed by an experienced abdominal wall surgeon with a careful history. Treatment is also very simple, a small incision will be made to “cross” the surgical incision of the endometrium can be completely removed, as long as the clean cut will not recur. Ms. Zhao underwent the surgery successfully, and since then there has been no more painful lumps with the menstrual cycle.