Degrees of cervical dysplasia

When diagnosing cervical intraepithelial neoplasia, also known as interstitial neoplasia, or - in a more conventional definition for "domestic dysplasia of cervical dysplasia" - it is common to determine the level of pathological tissue growth. And depending on this, degrees of cervical dysplasia are distinguished.

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The main degrees of cervical dysplasia

Cervical dysplasia of 1 degree - CIN I (by Pap smear LSIL) or cervical dysplasia of mild degree - is determined when patients are diagnosed with HPV - papillomavirus, which causes cervical oncology in 99% of cases. In this case, insignificant proliferation is detected in the epithelial cells of the lower 30% basal layer, and in the upper layers the cytopathic effect of the papilloma virus is observed: atypical cells with periconial cavitation or halo in the cytoplasm.

This is the least dangerous degree of dysplasia. Foreign gynecologists note that treatment of mild degree (CIN I) is not recommended if the process lasts less than two years: the patient's immunity can cope with HPV within 12 months. Although it all depends on the state of the body's defenses.

Dysplasia of the cervix of the 2nd degree - CIN II (by Papillary Smear HSIL) - or dysplasia of the cervix of the moderate degree differs from the first degree by a deeper lesion of the epithelium (by 50% of the thickness). In this case, the affected part of the epithelium consists of undifferentiated cells changed in shape and size.

Cervical dysplasia of the third degree, covering 70-90% of the thickness of the epithelium, is defined as severe dysplasia of the cervix or CIN III (HSIL by cytology). Dysplastic cells are most often distributed throughout the entire thickness of the ectocervix.

Atypicality in the form of nuclear and cytoplasmic changes in cells of epithelial tissue is expressed in an increase in their mitotic division, in which the nuclei increase and intensively stain, which is an anomaly for epithelial cells. Hyperchromatosis of the nuclei confirms the intensive multiplication of epithelial cells, characteristic of neoplasia. Moreover, differentiation and stratification may be completely absent or be present only in the upper layer of the epithelium (with numerous mitosis).

This pathology is often defined as carcinoma in situ, but the degree of CIN III is not yet a cancer, but a precancerous condition. If severe dysplasia of the cervix is not treated in time, it can spread to neighboring normal tissues and become cancer. According to NCI, in 20-30% of cases such dysplasia undergoes malignancy and leads to squamous cell carcinoma.

But dysplasia of the cervix of the 4th degree is an invasive cancer. In the past it was believed that the progression of this pathology towards cancer occurs through all these degrees of cervical dysplasia in a linear order. According to NCI, progression to invasive cervical cancer occurs in approximately 1% of cases of first degree dysplasia, 5% of cases of the second degree and at least 12% of severe dysplasia.

The overall malignancy level of dysplasia is approximately 11% of cases of mild degree of pathology and in 22% - at a moderate degree. At the same time, spontaneous regression of the disease is observed within 12 months in almost 70% of patients with mild degree of dysplasia, and within 24 - in 90%. About 50% of cases of moderate cervical dysplasia also tend to spontaneously regress.

How do degrees of cervical dysplasia differ?

Previously, the pathological changes in the flat epithelium of the cervix - the degree of dysplasia of the cervix - were defined as mild, moderate or severe. But for more than a quarter of a century the terminological system proposed by the American National Cancer Institute (NCI) has been developed, developed in accordance with the American Cytology Society's (CSC) Atlas of Cervical Cytology Atlas, periodically reprinted by the American publishing house Bethesda Softworks (therefore the system is called Bethesda system).

The authors of the system tried to unify the definitions of the results of cytological studies of cervical ectocervix performed by Pap smear (Pap smear) and histological examination of a tissue sample (biopsy). Cytological changes in dysplasia are defined as a lesion of the flat epithelium (SIL) and have degrees: low (LSIL), high (HSIL), possible cancer (malignant) and atypical glandular cells (AGC).

Histological changes are expressed by the term cervical intraepithelial neoplasia (CIN), their degrees - I, II and III.

The descriptive system still uses the terms: mild dysplasia, moderate grade dysplasia of the cervix and severe dysplasia of the cervix.

When the doctor indicates that the patient having undergone dysplasia of the cervix of grade 0, this means: the result of the cytological analysis shows normal squamous epithelium, and the histology also did not reveal pathological changes in the cervical tissue.