Cytology of the vaginal smear
Cytological examination of a vaginal smear is performed to evaluate the function of the ovaries. Depending on the ratio of cells of different layers of the epithelium, 4 types of cellular reactions are distinguished in smears, which allow to judge the functional state of the ovaries.
■ I type. Smears that reflect a significant estrogen deficiency consist of basal cells with large nuclei and leukocytes;cells of the overlying layers are absent.
■ Type II.With an average degree of estrogen deficiency in smears, parabasal cells with large nuclei are predominantly determined;leukocytes are either absent or few;there may be basal and intermediate cells.
■ III type. With a slight estrogen deficiency in the smear, the cells of the intermediate layer with medium nuclei, single surface cells and basal layer cells are mainly contained.
■ IV type. With sufficient estrogen secretion, the smear consists of surface epithelial cells.
In clinical practice, smears can not always be attributed strictly to one type or another. Sometimes there are mixed patterns that are classified as intermediate types. In addition, the type of smear depends on the phase of the menstrual cycle. In the normal ovarian-menstrual cycle, during the proliferation phase, type III of the smear is observed, and during the ovulation period, type III or IV is observed.
Investigation of vaginal smear to address the question of the functional status of the ovaries can not be performed with inflammatory discharge, after vaginal manipulation and with intravaginal injection of drugs.
The following indices are used to more accurately estimate the hormonal stimulation by the cytological method.
■ Karyopicnotic index( KPI) is the ratio of surface cells with pycnotic nuclei( less than 5 μm) to surface cells with nuclei greater than 6 μm. With a normal reaction of the pH of the vagina, the KPI value( %) strictly depends on the phase of the ovulatory menstrual cycle( Table).
Table KPI indicators during the ovulatory menstrual cycle
Days of the menstrual cycle
Table KPI indicators during the ovulatory menstrual cycle
Days of the menstrual cycle
■ Atrophic index - the ratio of the number of cells of deep layers( basal and parabasal) to the total number of cells.
■ Intermediate cell count - the ratio of the number of intermediate cells to the total number of smear cells.
■ Eosinophilic index( acidophilic) - the ratio of surface acidophilic cells to surface basophilic cells. The stronger the estrogenic stimulation, the more it appears in the smears of superficial eosinophilic-staining cells.
■ Maturation index - differential count of cell populations, expressed as a percentage. When calculating the maturation index, the smear should include only loose cells with normal morphology. The higher the degree of maturation of the epithelium, the more
in the smears of cells with a high maturation index and the higher will be the total amount obtained when calculating the cellular composition of the smear.
For deducing indices, consider not less than 200 cells. The result is expressed as a percentage. The most important is KPI, the indicators of which more closely coincide with the level of hormone release. During the normal menstrual cycle, CRI changes as follows: during menstruation to 80-88%, in the progesterone phase to 20%;in the luteal phase up to 20-25%, that is, it is the maximum for IV type of vaginal smears.
The atrophic index is high( 50-100%) for types I and II of the vaginal smears;the index of intermediate cells reaches 50-75% for types II and III, and the rise of the eosinophilic index( up to 70%) is observed during ovulation. Evaluation of the colpocytogram is carried out according to the Vidal scheme presented in Table.
Table Vidal Score for Colpocytogram Evaluation [Cost EA, 1975]
Table Vidal Score for Colpocytogram Evaluation [Cost EA, 1975]
It should be noted that inRecently, the cytological method of assessing the function of the ovaries is replaced by the determination of the concentration of sex hormones in the blood.
In addition to assessing the functional status of the ovaries, the cytological examination of swabs from the vagina is important for identifying atypical cells. Signs of the latter include: polymorphism of cells and their nuclei, pronounced anisochromia of the cytoplasm, nuclei, an increase in the nuclear-cytoplasmic index, uneven, rough distribution of chromatin in cells, an increase in the number of nucleoli, and the detection of figures of mitotic division. The formulation of a cytological conclusion is important for a correct assessment by clinicians of the data obtained. The most widespread in the world was the classification of cytological findings of the Pap smear. It includes 5 groups.
■ I group - there are no atypical cells. A normal cytological picture that does not cause suspicion.
■ II group - a change in the morphology of cellular elements due to inflammation.
■ III group - there are single cells with anomalies of the cytoplasm and nuclei, but the final diagnosis can not be established. It is necessary to repeat cytological examination, on the recommendation - histological.
■ IV group - detect individual cells with obvious signs of malignancy: abnormal cytoplasm, altered nuclei, chromatin aberrations, increase in the mass of nuclei.
■ V group - a large number of typically cancer cells are present in smears. The diagnosis of malignant process is beyond doubt.