To improve the outcome of malignant tumor patients, the key lies in early detection, early diagnosis and early treatment. However, it is not easy to achieve the “three early stages” because the early stages of tumors can be completely asymptomatic, or no lesions or cancerous tumors can be detected, or their nature can be difficult to determine. Another issue worthy of attention is the process of transition from normal cells or tissues to cancer cells or tissues, or in the state of benign or malignant interstitial zone, which is a lesion between under the eyes of Dr. Xun Aihua of the Department of Obstetrics and Gynecology, Jiangsu Provincial Hospital of Integrative Medicine, and under the microscope of pathologists, and we call them precancerous lesions and junctional tumors. If these lesions can be captured or accurately detected, and timely and correct intervention and treatment can be carried out, it will definitely make the prevention, diagnosis and treatment of cancerous tumors a step ahead. Therefore, recognizing and dealing with precancerous lesions and junctional tumors is an important issue in the prevention and treatment of malignant tumors. I. Basic concept and significance of precancerous lesions and junctional tumors Precancerous lesions are the process of developing from normal cells or tissues to cancerous cells or tissues, which usually has a continuous time, for example, it takes about 10-20 years from CIN to cervical cancer, and about 10 years from endometrial atypical hyperplasia to endometrial cancer. This is a time when intervention or interruption is possible and is an important stage for early prevention and treatment of cancer. In contrast, junctional tumor is actually a state in which there is cellular abnormality, or cellular anisotropy, but no destructive interstitial infiltration. This is the most important difference from infiltrating carcinoma. It can be considered that junctional tumors have Low Malignant Potential (LMP). The basic concepts of both are illustrated in the diagram below. Although both precancerous lesions and junctional tumors have heterogeneous cells or atypical proliferation, the origin and fate of the two are different. In contrast, most junctional tumors do not progress to cancer and remain junctional even if they recur. It may be of multicentric chemogenic origin, unlike infiltrative epithelial carcinoma of monocentric origin. In the treatment of precancerous lesions and junctional tumors, the basic principles are positive attitude and conservative approach, that is, from the perspective of cancer prevention and malignancy prevention, the treatment should be positive, such as removing the tumor and eliminating the lesion; and according to the extent of the lesion and the patient’s age and marital status, the uterus or ovaries should be preserved, which is different from the treatment of cancer, and is also the important significance of early detection of precancerous lesions and junctional tumors. Pre-cancerous lesions in the female genital tract can be basically expressed by intraepithelial neoplasia (IN), namely vulvar intraepithelial neoplasia (VIN), vaginal epithelial neoplasia (VAIN) and cervical epithelial neoplasia (CIN), and even the probability of ovarian epithelial neoplasia (OIN) has been proposed. Among them, CIN is the most significant and has been studied most frequently. The risk of CIN developing into carcinoma in situ and invasive carcinoma is 20 and 7 times higher than normal, respectively, and the risk of CINI, CIN II and CIN III developing into carcinoma is 15%, 30% and 45%, respectively, and CINI or CIN II can even develop into invasive carcinoma directly without going through CIN III (including CIS in situ). Therefore, the “three-step” examination including cytology-colposcopy-histology is very important in order to detect CIN accurately and timely, and to treat it appropriately according to its grade. Both VIN and VAIN are rare or poorly studied. However, there is a clear trend toward increased and younger incidence of vulvar, vaginal and cervical intraepithelial neoplasia, mainly due to human papillomavirus (HPV) infections, especially high-risk HPV infections. The chance of HPV infection in normal people is less than 4%, while the chance of infection in CINI, CINI and CINI! is 30%, 55% and 65% respectively, and cervical cancer is 99.8%. HPV infection increases the relative risk of cervical cancer by 250 times. HPV DNA is also detected in all CIN III and VAIN III, and 75% to 93% is HPV-16 DNA, so HPV DNA testing is an integral part of screening or detection of precancerous lesions in the female reproductive tract. In addition, studies in molecular biology have found that overexpression of P53 protein, significant increase in emblematic vascular density (MVD) and vascular endothelial growth factor (VEGF) also suggest aggravation of lesions or cancer. The success of HPV vaccine not only provides a powerful weapon for the application of HPV vaccine in genital tract cancer or precancerous lesions, but also shows a bright future for the prevention and treatment of the whole cancer. Endometrial hyperplasia is divided into simple hyperplasia (SH), compound hyperplasia (CH) and atypical hyperplasia (AH), with cancer rates of 1-3% (mean follow-up 15 years), 3-4% (mean follow-up 13 years) and 23% (mean follow-up 11 years), respectively. AH differs from SH and CH in terms of cellular heterogeneity and is classified as mild, moderate or severe AH, with cancer rates of 15%, 24% and 45%, respectively. Hand P 45%. With increasing age, the carcinogenic potential increases and the number of poorly differentiated types increases. Therefore, early diagnosis and treatment of endometrial hyperplasia are also advocated to improve the chances of conception and reduce the risk of carcinoma. Highly effective progesterone usually has a good remission rate and good pregnancy outcome, but the endometrium should be monitored closely, and it is not uncommon for hyperplasia or carcinoma to reappear even after pregnancy. Among trophoblastic diseases (GTD), hyperemesis gravidarum (HM) and placental site trophoblastic tumors (PSTT) are generally considered to have a propensity for malignancy. PSTT is an intermediate type of trophoblast, often expressing hpL without high levels of β-hCG, and is resistant to chemotherapy, so treatment is mainly surgical. Junctional tumors In the classification of female genital tract tumors, junctional tumors have the most prominent “status” in ovarian tumors, and were included as a separate pathological type as early as 1973, although there has been controversy, but the new WHO classification in 1999 still preserved this designation. The key lies in the recognition of micropapillary plasmacytoma of the ovary (MPSC), which is invasive and implantable and should be regarded as a subtype of plasmacytoma, while atypical proliferative plasmacytoma is non-invasive and belongs to the subtype of plasmacytoma. It is non-invasive and benign. If the two are separated, the so-called nature, prognosis and management can be easily distinguished. Mucinous junction tumor (MBT) of ovary is divided into intestinal type (IMBT, 85%) and cervical canal type (Miller’s canal type, MMBT, 15%), and whether interstitial infiltration exceeds 5 mm is a marker to distinguish IMBT from invasive mucinous carcinoma. In basic studies, it is believed that the risk of recurrence and death is increased 4-fold and 6-fold in those with P53 overexpression. DNA diploidy is common and has a good prognosis; a few aneuploidies have a poor prognosis. Therefore, it is generally said that ovarian junctional tumors have low malignancy, long survival time, late recurrence, and recurrence usually remains junctional. 5-year survival rate is more than 90%. Younger patients can preserve fertility and postoperative chemotherapy is not advocated and should be considered only in advanced stages, with peritoneal infiltrative implants, aneuploid DNA and with p3 overexpression as an adjunct to chemotherapy. Uterine junctional smooth muscle tumor is not a very definite concept. However, some scholars believe that there is a group of junctional tumors between common uterine smooth muscle tumor (UL) and uterine smooth muscle sarcoma (LMS), and the pathological diagnosis is mainly based on three histological features: cellular abundance, cellular heterotypy and nuclear division. The main types are rich in cells (CL), bizarre type (BL) and nuclear division active type (MAL). They differ pathologically from sarcomas in that the latter have nuclear divisions ≥10/lOHPF, significant cell heterogeneity, and coagulative necrosis. Junctional smooth muscle tumors of the uterus have the same clinical features as smooth muscle tumors, have a good prognosis and are managed in the same way, with myomectomy being feasible for those with fertility requirements: however, continued follow-up is clearly advisable. Endometriosis (endometriosis) is a benign disease, but can undergo histological changes to become cancerous. As early as 1925 Sampson described the malignancy of endometriosis and proposed three diagnostic criteria. Later Scott (1953) highlighted the histological pattern of transition from endoheterosis to malignant tissue. The concept of atypical endometriosis, in which heterogeneity of endometrial glands is the main feature and migration to malignant epithelium, has been proposed until 1988 and can be considered as a junctional state, which may play an important role in the development of ovarian malignancies in combination with endometriosis. Endoheterozygous malignancies are mainly in the ovary, with endometrioid and clear cell carcinomas of the ovary being the most common. The concept of atypical endometriosis increases our understanding of the malignant biological behavior and malignancy of endometriosis, which is generally reported to be l%. In summary, the diagnosis and treatment of precancerous lesions and junctional tumors play an important role in the prevention and treatment strategy of cancer. This includes the molecular mechanism, cytology and histomorphology of their occurrence and development, and only a profound understanding can lead to effective intervention measures. Second, to strengthen the communication, communication and cooperation between clinicians and pathologists. Precancerous lesions and junctional tumors are mainly based on cytological and histological detection and observation. Pathologists should pay attention to clinical materials, and clinicians should know more about the language of pathology, understand its results and reports, and guide clinical management, decide on surgical methods, chemotherapy application and follow-up, etc. Third, to strengthen the standardization of clinical work, accumulate experience and improve the diagnosis and treatment. Although precancerous lesions and junctional tumors are the result of pathology report, their clinical diagnosis and treatment procedures are very important, such as the examination process for cervical lesions, which must be standardized, and continuously improved and perfected. The diagnosis of abnormal uterine bleeding and postmenopausal bleeding, and the cleaning and examination of gravida should also have operating procedures in order to be comprehensive and accurate. It is endometriotic cysts in the ovary, alert to their malignancy, should also be listed several items for reference, such as cyst diameter >10cm or a significant trend of increase; postmenopause and recurrence, change in pain rhythm, progression or persistence of dysmenorrhea; imaging examination reveals substantial or papillary structures; excessive serum CAl25 (>200iu/ml/. The cyst should be routinely examined during surgery and sent for frozen section if necessary, etc. Clinicians should be good at comparing surgical findings, specimen review and later pathology reports to increase their ability and experience in determining the nature of the tumor and improve the diagnosis and treatment.