Atypia in Gynecology

Methods for obtaining material for examination

The basis for diagnosing any pathological changes is the proper collection of cells and tissues. Two principal approaches are used in gynecological practice.

The first is cytological examination. The method is based on the analysis of the structure of the cells themselves, their quantitative proportions, and their mutual arrangement under a microscope. The material includes smears from the surface of the cervix, aspirates from the uterine cavity, as well as punctates (e.g., fluid from the rectouterine pouch or the contents of pelvic masses). Cytology serves as the main screening method during mass preventive examinations; however, its significant drawback remains its relatively low sensitivity, reaching only 60–70%.

The second approach is a biopsy, which is the vital excision of a small tissue fragment for more detailed study. It is indicated when a malignant process is suspected in the cervix, vagina, or external genitalia. Biopsies can be:

• Excisional (excision of a piece of tissue);
• Targeted (performed under strict visual control, for instance, during colposcopy or hysteroscopy);
• Puncture.

Evaluation of atypia using the Papanicolaou system

In Russian practice, descriptive conclusions are sometimes used, but the most widespread is the unified Papanicolaou system, or Pap test. It divides all identified cellular changes into five classes:

1. Class I — completely normal cytological picture.
2. Class II — reactive or inflammatory changes in the squamous epithelium are detected.
3. Class III — atypia of individual epithelial cells is registered, raising a serious suspicion of dysplasia development.
4. Class IV — isolated cells with clear signs of malignancy are discovered.
5. Class V — entire complexes of malignant cells are identified, indicating the presence of cervical cancer.

Features of gynecological cancer progression

The detection of atypical cells is the first step toward understanding the stage of the tumor process. Different localizations have their own patterns of malignant neoplasm development:

• Cervical cancer: The process begins with cervical intraepithelial neoplasia (CIN) and gradually progresses to invasive cancer. An important criterion is the depth of invasion. The microinvasive stage IA1 is characterized by stromal invasion of no more than 3 mm, while stage IA2 ranges from 3 to 5 mm. If the depth reaches 5 mm or more, a macroscopic tumor of stage IB is diagnosed. From a clinical perspective, the current ratio of detected pre-invasive to invasive cancer cases is considered extremely unfavorable — carcinoma in situ should be diagnosed much more frequently to prevent the development of advanced forms.
• Vaginal cancer: Progresses through stages from stage 0 (pre-invasive carcinoma) to stage IV, when the tumor invades the urinary bladder or rectum and produces fixed metastases.
• Ovarian cancer: In 80–85% of cases, secondary cancer is diagnosed (e.g., cystadenocarcinoma), which forms against the background of prior pathological changes in the organ.

Atypia and malignant growth in the mammary gland

Breast pathologies are often considered in the context of women's health. The morphological changes identified here are also divided into non-infiltrating and infiltrating.

Non-invasive forms include ductal carcinoma in situ (growth of atypical epithelium inside the ducts without breaching the stroma, forming solid, papillary, or cribriform structures) and lobular carcinoma in situ (clusters of cells with rounded nuclei and clear cytoplasm in the terminal duct lobular units).

Invasive cancer is most commonly ductal — macroscopically it forms a dense node (scirrhus) that resembles "raw potato" when cut. Medullary carcinoma with prominent lymphocytic infiltration and the rare colloid carcinoma, which forms mucous "lakes" with groups of tumor cells, are also distinguished. When the probability of malignancy is high (e.g., BI-RADS category 5), a definitive diagnosis is made exclusively on the basis of a biopsy.

Class and exam questions

What else to study on this topic

• Morphological characteristics of cervical intraepithelial neoplasia (CIN).
• Features of development and histological structure of ovarian cystadenocarcinoma.
• Differences between ductal and lobular breast carcinoma in situ.
• Stages of microinvasive cervical cancer and exact criteria for stromal invasion depth.
• Clonal evolution and morphogenesis of squamous cell carcinoma.

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.