see also >> infezione da HPV
What can a Pap test diagnose? The Pap test is useful for finding cancerous
cells, and other precancerous cells and inflammation of cervical and vaginal
cells. This test, designed by the great Greek-American doctor Georgios
Papanicolaou, is used for the rapid diagnosis of cervical cancer. In addition,
the Pap test can give useful indications on hormonal balance, and allow the
recognition of vaginal infections (see vaginal discharge or leukorrhea). There
is no woman who does not have to do it!
In the vaginal secretion elements of different origins are normally present:
- Vaginal epithelial cells
- Cervical epithelial cells
- Endometrial cells
- Polymorphonuclearates
- Lymphocytes
- Histiocytes
- Red blood cells
- Germs of flora
- Mucus
The vaginal secret smear test allows you to have ideas about the hormonal
situation of the woman, since the vagina is a specific receptor of sex hormones
also allows you to have knowledge about the atypia of the exfoliated cells. The
secretion is taken with a spatula or with a loop and is swiped on a slide and
after appropriate fixation is colored. Vaginal epithelium can be considered the
mirror of ovarian activity with high sensitivity to estrogen and progesterone
action.
The epithelium of the vagina is of a pavement type, stratified like the one
covering the harness and consisting of 3 layers:
- basal layer, still divided into deep basal or parabasal and external basal
- intermediate layer
- superficial layer
Normally it is not possible to find cells of the basal layer; this happens in
pathological conditions when the hormonal action of estrogens or in the
climacteric is lost. The cells of the ion mediated layer appear in the
pre-menstrual and post-menstrual phases, the cells of the superficial layer are
eosinophils in the menstrual estrogenic phase and pleated and basophilic cone in
the luteinic phase. There are other cells called navicular that are present in
pregnancy and in the pre and post-menstrual phases. Other things to evaluate are
the post-menopausal and cervical type androgen cells, the eosinophilic elements
and those with a cariopycnotic nucleus (eosinophilic index and cariopycnotic
index). Thus there are three types of smear:
 Atypical cells with thickened and intensely colored nuclei |
 Vaginal smear cells in the norm |
| negative | no evidence of tumor cells |
| LSIL | low-grade intraepithelial squamous lesion cells |
| HSIL | high-grade squamous intraepithelial lesion cells |
| AIS | Glandular cells suspected for in-situ adenocarcinoma of the cervix |
| carcinoma |
suspicious cells for infiltrating tumor
|
| ASC-US |
abnormal squamous cells, not further classifiable
|
| ASC-H |
abnormal squamous cells, an HSIL is not excluded
|
| AGC | glandular cells (endocervical or endometrial) abnormal, a tumor can not be excluded |
- the atrophic smear due to a poor epithelium due to estrogen deficiency
- the estrogenic strip, with superficial eosinophilic cells and little mucus
- luteinic smear, of the secretive phase of the menstrual cycle, with cells of
the intermediate layer, prepycnotic or picnotic.
The exfoliative properties of the vaginal epithelium and of the uterine portal and the less evident properties of the endocervical and endometrial epithelium are instead valuable for the study of cellular atypia that can occur at these levels, for the purpose of early diagnosis of cervical cancer. Still allows the PAP test to study the mucus that increases in the phase towards the 12th -15th day of the cycle, ovulatory phase, mucus that gives rise to the phenomenon of "Spinnbarkeit", that is particularly filamentous and that extends between the fingers. It is highlighted by placing the mucus between two slides, when the mucus dries and appears to "fern leaf".
Cellular atypia can be highlighted with cytology and may be present:
- charged to the nucleus
- charged with the cytoplasm
- charged to the whole cell
The atypical nuclei are larger than the norm, intensely colored and with
thickened chromatin, as of discariotic cells in carcinoma in situ, irregular,
tadpole, etc.
There are V classes:
Class I, negative
Class II, due to inflammatory cells
Class III, doubtful, for some atypical cells
Class IV, positive: presence of atypical elements
Class V, absolutely positive with malicious elements
Today the report, until yesterday numeric, is communicated with a synthetic
description of the state of the cells.
In Italy the recommended and most frequently used classification is the Bethesda System 2001 (TBS 2001) which
divides the test results into:
Finally, it is thought that the PAP test, given the correlation of cervical
cancer with the human papilloma virus, (HPV) that led to the development of
biomolecular diagnostic techniques, characterized by a high sensitivity (more
than 95%). Particularly promising appears the prospect of the vaccine, which
however currently seems to confer immunity for only 4 years. However, HPV
vaccines are currently targeting only the most common types of cancer oncogenic
virus (HPV 16 and 18) which alone are responsible for about 70% of cervical
cancers. Other types of HPV with high or intermediate oncogenic potential are
not yet included, responsible for the remaining 30% of tumors, whose biological
behavior following the introduction of the vaccine can not yet be foreseen. It
is therefore necessary that even vaccinated women continue to undergo screening
with the pap test.
index of clinical sexology