What is it?
Cervical Intraepithelial Neoplasia (CIN) is a group of cervical epithelial lesions (dysplasias) characterised by morphological and histological changes that do not extend beyond the basal membrane. A distinction can be made between:
CIN 1 (dysplasia affecting the cells of the deepest layer of the epithelium)
CIN 2 (moderate dysplasia, where cellular atypia covers 2/3 of the cervical epithelium)
CIN 3 (severe dysplasia and Ca in situ, in which the entire thickness of the epithelium is involved, without going beyond the basal membrane. When the basal membrane is exceeded, we speak of an invasive carcinoma).
The new Pap test classification (Bethesda) uses the term SIL (Squamous Intraepithelial Lesion), dividing the dysplasia into:
Low-SIL, which includes CIN 1 (mild dysplasia)
High-SIL, which includes CIN 2 (moderate dysplasia) and CIN 3 (severe dysplasia).
Each of these lesions has a regressive (very high in cases of mild dysplasia) and progressive (about 1% in cases of mild dysplasia, 5% in moderate dysplasia and 12% in severe dysplasia) probability.
High-grade dysplastic lesions (H-SIL) are most frequently diagnosed in women between the ages of 25 and 35, while invasive cancer is most frequently diagnosed in women over 40. In almost all cases, a low-grade dysplastic lesion takes several years to develop into an invasive cervical cancer. This implies the need for early diagnosis and, therefore, treatment of these lesions.
The most common risk factor for cervical dysplasia is genital infection with human papillomavirus (HPV). Other risk factors are as follows: sexual promiscuity, smoking, use of medicines that suppress the immune system.
There are several subtypes of HPV. The high-risk subtypes (16, 18, 31, 33, 35, 39, 45, 46, 51, 52) are found in dysplasia or preneoplastic lesions, low (L-SIL) or high (H-SIL), and many malignant diseases of the female lower genital tract, such as carcinoma of the cervix, vagina and vulva. HPV subtypes 16 and 18 alone are responsible for 70% of cervical cancers.
Which are the symptoms?
Cervical dysplasia is completely asymptomatic. HPV infection is also asymptomatic. The evolution of dysplasia into cancer can be manifested by spotting, intermenstrual bleeding and foul-smelling vaginal discharge that is not justified by other causes.
How is it diagnosed?
In cases where a screening examination (Pap test and/or HPV test) reveals a cytological abnormality, colposcopy is the next diagnostic step. Colposcopy is an outpatient examination that is easy to perform and risk-free for the patient, aiming at a precise observation of the vagina and cervix. During colposcopy, one or more biopsies can be taken at the site of the lesion in order to obtain an anatomo-pathological opinion of the dysplasia, which will be useful for the subsequent clinical management of the patient.
How is it treated?
The most common treatments for cervical dysplasia are laser, cervical diathermocoagulation and conization (LEEP).
Treatment is divided into destructive or ablative (laser vaporisation and diathermocoagulation of the cervix, in which pathological tissue is destroyed) and excisional (conization, in which pathological tissue is removed and examined by a pathologist). Factors influencing the choice of treatment include the degree and severity of dysplasia, the age of the woman, her desire to get pregnant in the future and the possible presence of other gynaecological problems.
The goal of cervical dysplasia treatment is to remove the lesion and stop progression to cervical cancer. However, regardless of treatment, there is a possibility of dysplasia recurring. Depending on the type of lesion diagnosed, periodic check-ups after treatment are necessary (colposcopy with cytology and HPV molecular-biological test).
The prevention of cervical dysplastic lesions has been made possible by the introduction of the HPV vaccine. Studies on the use of this vaccination, originally recommended only for girls and adolescents, have shown its usefulness for all women under 45 years of age, regardless of their clinical history of papillomavirus positivity and/or history of cervical dysplastic lesions. In adults, vaccination includes 3 doses at 0, 2 and 6 months of age (should be avoided during pregnancy).
Where do we treat it?
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