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CYT 2113 Cytology I
Lesson 9:
Basic Gynecological Cytology
Pap Test
Part of a gynecological exam
An examination under the microscope of cells
scraped from the tip of the cervix
Features to be Evaluated in a Pap test
Adequacy
Presence of abnormal cells
Number and distribution of abnormal cells
Relationship between cells Relationship between cells
Cell size and shape
Nuclear size and shape
Nuclear changes and nucleoli
Nuclear-to-cytoplasmic (n:c) ratio
Cytoplasmic features Cytoplasmic features
Background or diathesis
Features of Preneoplastic and
Neoplastic cells
Abnormality in size and shape of cells
Variation in cell size and shape
Increase in nuclear size Increase in nuclear size
Increase in nuclear membrane irregularity
Hyperchromasia
Prominence of nucleoli and irregularity in
shape thereof
Thickening of nuclear membrane Thickening of nuclear membrane
Increase in n:c ratio
Cytoplasm scanty
Mitosis, increased number and abnormal
forms
Noncohesiveness Noncohesiveness
Common Causes of False-negative
Pap test
Atypical endocervical cells
Crowded cell aggregates
Cytolysis
Intermediate cells with nuclear enlargement Intermediate cells with nuclear enlargement
Metaplastic-like cells
Necrotic debris
Artifacts such as obscuring blood,
inflammation or air-dryinginflammation or air-drying
Common causes of false-positive
Pap test
Atrophic smear
Atypical endocervical or endometrial cells
Multinucleated cells
Perinuclear halo in nonkoilocytes
Reactive/repair
Squamous metaplasia
Tubal metaplasia
Differential diagnosis of cells with
naked nuclei
Naked nucleus - A nucleus in a cytologic
preparation that is virtually devoid of
cytoplasm
Autolysis of cytoplasm in menopause
Cytolysis
Degeneration, especially of endocervix
Reserve cells with tamoxifen treatment
Differential diagnosis of giant
multinucleated cells
Histiocytes
Atrophy
Folic acid deficiency
Tissue repair
Viral infection
Granuloma
Radiation Radiation
Syncytiotrophoblast (the outer syncytial layer
of the trophoblast that actively invades the
uterine wall forming the outermost fetal
component of the placenta)
Squamous carcinoma
Choriocarcinoma
Uterine sarcoma
Cytological features of dark-cell
clusters
Crowded with piling up of cells
Hyperchromatic overlapping nuclei
Anisonucleosis
Scant cytoplasm Scant cytoplasm
Increased n:c ratio
Mitosis present
Often difficult to determine whether
squamous or glandular
Differential diagnosis of dark-cell
clusters
Reactive endocervical cells
Tubal metaplasia
Atrophy: nuclear membrane smooth
Benign endometrial cells Benign endometrial cells
Atypical squamous cells cannot exclude high-
grade squamous intra-epithelial lesion
High-grade squamous intra-epithelial lesion:
nuclear membrane irregularnuclear membrane irregular
Adenocarcinoma in situ
Endocervical or endometrial carcinoma
Differential diagnosis of small cells
Lymphocytes in chronic lymphocytic cervicitis
Degenerated cells
Endometrial cells
Histiocytes Histiocytes
Reserve cells
Tamoxifen cells
Smaller cell type of squamous-cell carcinoma
Small-cell anaplastic carcinoma
Differential diagnosis of cells with
macronucleoli
Repair, regenerative or reactive squamous
cells
Reactive endocervical cells
Viral inclusions Viral inclusions
Treatment effect
Adenocarcinoma
Metastatic tumour
Nonkeratinizing squamous carcinoma
Differential diagnosis of
adenocarcinoma
Viral infections
Endocervical cells, benign and atypical
Endometrial cells, benign and atypical
Endometritis Endometritis
Histiocytes
Metaplasia
Vaginal adenosis
Intrauterine device
Metastatic tumour Metastatic tumour
Factors Related to Failure of Pap
Test Screening
Patient
Clinician
Instrument and sample
Cytopreparation and interpretation Cytopreparation and interpretation
Lesion
These factors are interrelated
Patient-related Errors
Including failure of women to get regular Pap
tests or to seek any health care at all
Douching or sexual intercourse can
mechanically remove the superficial cell layers
that the Pap test samples, causing false-that the Pap test samples, causing false-
negative results due to sampling error
Some women delay seeking medical attention
even when they have symptoms that they
know are suspicious, such as abnormal vaginal
bleeding
Clinical Errors
Failure to take a Pap test at all
Failure to take an adequate Pap test
The sample must be obtained under direct
visualization, with considerable pressure
The speculum should not be lubricated The speculum should not be lubricated
excessively
Overzealous rubbing, swabbing or cleaning
the cervix before taking the sample can
remove the abnormal cells, leading to false
negative results
Well-trained health care providers, not
necessarily physicians, take better Pap tests
Failure of the clinician to provide pertinent
clinical data can severely compromise
cytologic interpretation of the Pap test
Failure to follow-up abnormal Pap test results
Failure to perform a biopsy of suspicious
lesion
Failure to investigate suspicious clinical
symptoms
Instrument and Sample Errors
A combination of spatula and brush enhances
sampling compared with either device used
alone
The material from which the sampling device The material from which the sampling device
is important
Cotton swabs and wooden spatulas tend to
trap cells so they unavailable for
interpretation
Wooden spatulas collect between 600,000
and 1.2 million epithelial cells, but less than
20% are transferred to the glass slide when
making a conventional Pap smear
The transfer of cells to the slides is random
and statistically prone to error because the and statistically prone to error because the
abnormal cells are not homogenously
distributed in the sample
Endocervical samples taken by cotton swabs
or with plastic spatulas obtain fewer atypical
cells than do endocervical brushes
The shape of the sampling device is also
important for obtaining an adequate sample,
particularly of the endocervix
Sufficient numbers of well-preserved cells
must be collected and the sample must be
representative, including the transformation representative, including the transformation
zone
A conventional Pap smear must be thinly
spread and immediately and properly fixed
Cytopreparation and Interpretive
Errors
Few abnormal cells (particularly
Lesion-related Errors
Some lesions fail to exfoliate sufficient
numbers of cells for detection
Small or inaccessible lesions may be difficult
to sample adequatelyto sample adequately
The shape of the cells and the quality of the
cervical mucus also affect the sampling
Pap tests are more often inadequate in
women with advanced epithelial
abnormalities
Necrosis, inflammation or bleeding may
obscure, alter or dilute the abnormal cells,
making interpretation difficult
Pap tests repeated within a short time (up to Pap tests repeated within a short time (up to
several weeks) have a particularly high false
negative rate
Apparently it takes some time for the lesion to
regenerate sufficient cells to be detected in
the cytologic sample
A negative following a positive
interpretation can mislead the clinician into
thinking the lesion has regressed or the
previous positive report was wrongprevious positive report was wrong
It is also possible that some tumours progress
so rapidly that they develop in between Pap
test screenings