1. The histological peculiarities of the cervix The cervical epithelium is composed of the squamous epithelium of the vaginal part of the cervix and the columnar epithelium of the cervical canal.
(1) Phosphoepithelium of the vaginal part of the cervix: it can be divided into 3 bands (basal band, intermediate band and superficial band) from deep to superficial. The basal zone consists of basal cells and parabasal cells. Immunohistochemical staining showed that the basal and parabasal cells contained epidermal growth factor receptor (EGFR), estrogen receptor (ER) and progesterone receptor (PR). Basal cells are reserve cells and do not show significant cell proliferation. However, they can proliferate when stimulated by certain factors, or they can proliferate into atypical squamous cells or differentiate into mature squamous cells, but not into columnar cells. The parabasal cells are actively proliferating cells with occasional nuclear division phase. The intermediate and superficial bands were completely non-proliferating differentiated cells, and the cells tended to die. The different biological characteristics of the cells in the 3 bands of cervical squamous epithelium explain the cellular origin of cervical intraepithelial neoplasia. (2) Cervical canal columnar epithelium: columnar epithelium is well differentiated cells, while subcolumnar epithelial cells are reserve cells with the ability to differentiate or proliferate, which are generally not seen in pathological sections.
There are two different ideas about the origin of subcolumnar epithelial reserve cells: ① Directly derived from columnar cells. The results of cell culture and cell growing experiments show that human columnar cells can differentiate in both directions, i.e. differentiate into CK7 and CKl8 positive mucus-secreting columnar cells and differentiate into CKl3 positive reserve cells; ② originate from basal cells of cervical squamous epithelium.
(3) Transformation zone and its formation: the intersection of cervical squamous epithelium and columnar epithelium is called squamous-columnar intersection or squamous-columnar intersection. According to its morphogenetic changes, the squamous-columnar junction is divided into the primitive squamous-columnar junction and the physiological squamous-columnar junction.
During fetal life, the squamous epithelium originating from the genitourinary sinus grows upward to the ectocervix and adjacent to the columnar epithelium of the cervical canal, forming the primitive squamous-columnar junction.
After puberty, under the effect of estrogen, the cervical development increases and the mucosal tissue of the cervical canal is ectropioned, i.e. the columnar epithelium of the cervical canal and its underlying mesenchymal components reach the cervicovaginal part, resulting in the outward migration of the primitive squamous-columnar junction. -The columnar junction is called the physiological squamous-columnar junction.
The area between the primitive squamous-columnar junction and the physiological squamous-columnar junction is called the migratory zone. After menopause, the estrogen level decreases, the cervix atrophies, and the primitive squamous-columnar junction retreats into the cervical canal. During the formation of the migratory zone, the columnar epithelium covering its surface is gradually replaced by squamous epithelium.
The mechanisms of replacement are.
(1) squamous epithelial metaplasia: When the squamous-columnar junction is located in the vaginal part of the cervix, the columnar epithelium exposed to the vagina is affected by vaginal acidity, and the undifferentiated reserve cells (seserue cells) of the columnar epithelium begin to proliferate and gradually transform into squamous epithelium, followed by the shedding of the columnar epithelium and its replacement by compound squamous cells, this process is called squamous epithelial metaplasia ( squamous metaplasia).
The squamous epithelium may occasionally differentiate into mature keratinized cells, but they are generally immature squamous cells with uniform size and shape, round shape and large nuclei, without obvious distinction between superficial, middle and underlying layers, and without nuclear deep staining, heterotypy or abnormal division phase. The squamous epithelium is different from the normal squamous epithelium in the vaginal part of the cervix, and the line of demarcation between the two is seen on microscopic examination; it is also different from the atypical hyperplasia, and therefore should not be confused. The glandular epithelium of the cervical canal may also be squamous and form squamous glands.
(2) Squamous epithelialization: Squamous epithelium in the vaginal part of the cervix grows directly between the columnar epithelium and its basement membrane until the columnar epithelium is completely shed and replaced by squamous epithelium, which is called squamous epithelialization (squamous epithelizatlon). It is mostly seen during the healing process of cervical erosion. The healed epithelium is indistinguishable from the squamous epithelium of the vaginal part of the cervix.
The mature chemosquamous epithelium in the migratory zone is relatively insensitive to stimulation by carcinogens. However, immature septic squamous epithelium is metabolically active, and under the stimulation of some substances (such as sperm, semen histone and human papilloma virus), poor cell differentiation, disorganized arrangement, abnormal cell nuclei and increased mitosis can occur, resulting in cervical intraepithelial neoplasia.
2.Diagnosis and treatment of cervical lesionsl Cervical lesions (cervical lesions) are one of the common diseases in women,l including inflammation, injury, tumor, and precancerous lesions, etc. The most common one is chronic cervicitis, the most serious one is cervical cancer, and the most critical one is precancerous lesions. The occurrence of cervical cancer is getting younger and younger, and precancerous lesions are becoming more and more common among young women. Therefore, it is necessary to treat cervicitis, to have regular cervical cancer screening and to properly deal with precancerous lesions.
2.1l Chronic cervicitis: mostly occurs in married women, but can also occur in unmarried non-sexual people. It may be related to their own estrogen metabolism. Childbirth, multiple abortions can cause damage to the cervical mucosa, and postpartum, menstrual periods do not pay attention to hygiene are prone to infection with bacteria or viruses. Excessive sexual intercourse or lack of hygiene can affect the self-cleaning effect of the vagina.
The local changes of the cervix are: cervical erosion, cervical polyp, simple hypertrophy of the cervix, and cervical retention cyst. Among them, cervical erosion is the most common.
Clinical manifestations: The conscious symptoms are not serious, but there may be increased leucorrhea with yellow or bloody odor. Sometimes there are also symptoms such as lumbago, abdominal cramps and lower abdominal pain.
In addition to topical medication for mild cases, most of them are treated with physical therapy, such as freezing, laser, microwave, electrocautery, etc.
The treatment of cervicitis is very important to prevent cervical cancer. And early screening and treatment of cervical precancerous lesions is the main means to prevent and treat cervical cancer. It may take about 8-10 years to develop from cervical precancerous lesions to cervical cancer. During this period, early detection and active treatment can achieve complete treatment for early cervical cancer. Regular screening is a powerful measure for early detection of cervical cancer.
3. Diagnosis and treatment norms of cervical precancerous lesions (cervical intraepithelial neoplasia CIN).
Appropriate treatment for CIN is a very critical initiative in cervical cancer prevention programs, and is as important as screening and handling abnormal screening results. CIN is a relatively common problem, especially among women in their reproductive years, and laboratory studies by the College of American Pathologists in the mid-1990s showed that each year more than 1 million women are diagnosed with low-grade cervical epithelial lesions, also called CIN1; about 500,000 are diagnosed with high-grade precancerous cervical lesions, called CIN2, 3. From the Kaiser Permanente Northwest health plan Updated data indicate that the incidence rate has decreased somewhat each year to about 1.2 per 1,000 for CIN1 and 1.5 per 1,000 for CIN2 and 3. On the one hand, irrational treatment can increase the risk of developing cervical cancer, and on the other hand, the chances of complications from overtreatment increase accordingly.
Overview of the 2006 management guidelines: The histological classification in these guidelines is a 2-level system, with CIN1 corresponding to low-grade lesions and CIN2 and 3 corresponding to high-grade precancerous lesions. Low grade squamous intraepithelial lesions (LSIL) in cytology are not equivalent to CIN1 in histology, and similarly, high grade squamous intraepithelial lesions (HSIL) in cytology are not equivalent to CIN2,3 in histology.
It is important to emphasize that guidelines can never replace clinical judgment and it is critical to realize this. In using this management guideline for an individual patient, we often have to rely on clinical judgment for the simple reason that it is impossible to construct a management guideline that is applicable to any situation.
3.1. Concept of cervical intraepithelial neoplasia l Cervical intraepithelial neoplasia (CIN) refers to precancerous lesions of the cervix, which include cervical dysplasia (atypical hyperplasia) and carcinoma in situ CIS of the cervix, both of which have epithelial changes of the same nature and different degrees. CIN is classified into three grades according to the degree of cellular abnormality.
CIN grade I: mild atypical hyperplasia of the uterine cervix; CIN grade II: moderate atypical hyperplasia of the uterine cervix; CIN grade III: severe atypical hyperplasia of the uterine cervix and/or carcinoma in situ of the uterine cervix.
The risk of CIN developing into cancer was:
CINⅠ: 15% CINⅡ: 30% CINⅢ: 45% Note: CINⅠ and CINⅡ can develop directly into invasive carcinoma without going through CINⅢ (or carcinoma in situ) stage.
l The evolution from cervical precancer to cancer is usually about 8-10 years. This would be an important and non-negligible time. The so-called cervical cancer is a preventable and curable disease, the key to which also lies in the timely diagnosis and correct management of this stage.3.2. Etiology of cervical intraepithelial neoplasia, epidemiological investigations have found that CIN is associated with the following factors.
Sexual disorders, smoking, premature sexual life (25mm person, not suitable.
Treatment of cervical intraepithelial neoplasia.
l 3. high-frequency electrosurgical excision procedure (loop electrosurgical excision procedure, LEEP) LEEP was first reported by Cartier in France in 1981 and became widely used in the 1990s. It is performed by removing the cervical tissue with round electrodes and the cervical canal with square and triangular electrodes with satisfactory results.
Another term for LEEP is large loop excision of the transformation zone-conization (LLETZ).
3.1 Indications for LEEP The indications for LEEP proposed in the literature include, on cytology and colposcopy, l) suspected CIN II-III; l) suspected early invasive adenosquamous carcinoma of the cervix or carcinoma in situ; l) patients with persistent CIN I, ASC or CIN I with inconvenient follow-up; l) symptomatic cervical ectopia l The problem with LEEP treatment is that too much tissue is removed. In order to be prudent, conization is performed for ≥CIN II; biopsy is performed for ASC and CIN I.
l 3.2 Scope of LEEP l For CIN II-III or carcinoma in situ, according to the literature, cold knife (scalpel) conization should be used for lesion diameter ≥2.5 cm; lesion diameter.