Endometriosis (endometriosis) affects 10-15% of women of childbearing age worldwide, with 3- 10% of them suffering from deep infiltrative endometriosis. Although this disease is not as common as ovarian chocolate cysts, its clinical symptoms are much more powerful than those of coeliacs. It is simply a progressive model of pain: pain during menstruation, pain during intercourse, pain during bowel movements, and even sudden vague pain in the stomach during daily eating, drinking, and sleeping. These annoying pains recur, causing not only physical discomfort, but also mental boredom and depression. We have received several such patients in our outpatient clinic, and today we will write an article to introduce you to this monster buried in your body: “deep nodular endoheterosis”. 1. Definition and pathogenesis of deep nodular endoheterosis We call it deep nodular endoheterosis when the lesion of endoheterosis infiltrates to a depth of ≥5 mm under the peritoneum or invades important organs such as the intestine, ureter and bladder. Patients often ask: Why do I have this disease? Unfortunately, we don’t know. There are still many medical theories about the cause of deep nodular endostosis, such as the implantation theory and the chemotaxis theory, something that involves molecular mechanisms that are still being explored by experts night and day. What we do know, however, is that the extent of lesions and depth of infiltration in deep nodal endografts are closely related to clinical pain symptoms. Dysmenorrhea and painful intercourse are caused by the increase in size of the endonodular lesion during menstruation or by the external force of sexual intercourse, which compresses the sensory nerves located in the area; chronic pelvic pain is caused by the local inflammatory reaction caused by the deeper growth of the endonodular lesion; if the lesion invades the rectum or ureter, it causes defecation and urination problems. When a patient with deep nodular endometriosis sits down to describe her symptoms to the doctor, the first clinical symptom usually mentioned is pain: dysmenorrhea, painful intercourse, painful defecation or chronic pelvic pain. If the doctor finds a painful nodule behind the vagina or the uterus, he or she can make a preliminary diagnosis. There are also patients who come to the clinic with other conditions unrelated to lower abdominal pain, such as vaginitis, and who receive clinical attention when a painful nodule is found during the gynecologic examination. What tests are prescribed by the doctor when the possibility of deep endocele is detected? Three-dimensional vaginal ultrasound and MRI are imaging modalities that assist in the diagnosis. Both imaging methods can indicate the size and extent of invasion of the lesion. When billing clinically, some patients ask: Can I just have a 3-D vaginal ultrasound? It is true that MRI is expensive, but according to researchers, the two imaging methods are complementary: a survey from Rome found that 3D vaginal ultrasound was more accurate (97%) in detecting lesions in the bladder and rectal fossa, while MRI was accurate in detecting lesions that invade the vagina and rectum. When the results of both imaging methods are available, a three-dimensional image is created in the doctor’s head: where the endometriosis lesions are, how deep they are infiltrated, and how they relate to the surrounding organs, and this three-dimensional image is especially important for the ensuing treatment. How should deep nodular endoheterosis be treated? For patients with painful symptoms and infertility, surgery is the treatment of choice, and all the surgeon has to do during surgery is remove the endoheteropathy lesion. Because of the advantage of the magnification of the laparoscope in identifying the lesion, the surgeon will first consider the possibility of laparoscopic surgery. However, this surgery is not as simple as myomectomy or ovarian cyst debridement. Endo causes the organs in the pelvis to adhere to each other, and the endo lesion is in the midst of the adhesions, so we have to separate the adhesions and cut out the endo lesion. It is also very common for the intestine and ureter to be invaded by the lesion. Preoperative imaging will tell us the depth of the lesion infiltrating the intestinal wall or ureter, and once it is determined that these organs need to be removed and repaired, a surgeon will be asked to complete the surgery together. 3. Recurrence of deep nodular endometriosis and medication problems Deep nodular endometriosis is a benign disease, but the recurrence rate is high. Patients often have high expectations for fertility and quality of life and cannot accept the recurrence of disease after surgery. However, it is worth noting that even with the risk of recurrence, the benefits of surgery are considerable. Foreign studies reported that after laparoscopic surgery to remove the lesion, the average follow-up was 8, 8 months, and the relief rates of dysmenorrhea, chronic pelvic pain, painful intercourse, and painful defecation were 59%, 87%, 77%, and 86%, respectively, indicating that the surgery had a significant effect on the improvement of symptoms. The surgeon will fully communicate with the patient before the operation to inform him/her of the risks and postoperative complications, and in the case of infertile patients, postoperative treatment for assisted reproduction is also required. During the consultation, we found that some patients are afraid of surgery and wish to be treated with medication. Unfortunately, there are no medications that can cure endometriosis. Under what circumstances would we recommend medication to a patient? Oral contraceptives, GnRH-a, progesterone, danazol vaginal ring, and Mannitol may be considered for patients who have a history of several previous endo-herpetic surgeries and need to postpone surgery, as well as patients who have difficult and risky surgical resections and need preoperative medications to make the lesion shrink. It should be clear that preoperative medication by itself cannot cure the disease, and postoperative medication only serves to retard recurrence. I have operated on a number of patients with deep nodular endometriosis during this period, and all of them have been followed up for at least two months after the surgery, and their pain symptoms have been relieved, which is encouraging according to the results of the surgery, and this is what motivates me to continue to serve these patients.