Pap smear (2)
-
Upload
deepthisekhar -
Category
Health & Medicine
-
view
2.478 -
download
3
description
Transcript of Pap smear (2)
PAP smear: named afterDr. George Papanicolaou (1883-1962)
Vaginal smears from guinea pigs (1917)
Women (1920)
Hormonal cyclesPathological conditions (1928)
Cytologic screening for cervical cancer
Usefulness of pap smear in the screening programme for cancer cervix is shown by the following:
Long latent period of 10-15 years between CIN and invasive cancer allows adequate treatment of CIN and prevention of invasive cancer
Proved successful in reducing the incidence of invasive cancer by 80% and the mortality by 70%
When to screenStart within 3 years of onset of sexual activity or by age
of 21, whichever is first.
High risk factors for cervical dysplasia:
Early onset of sexual activity
Multiple sexual partners
Smoking habits
Oral contraceptives
HPV and HIV positive women
Screening frequency
Yearly until three consecutive normal pap smears, then
may decrease frequency to every 2-3 years
Annual screening for high-risk women is highly
recommend.
When to stop routine screening
Age 70 and “adequate recent screening”
Three consecutive negative pap smears
No abnormal pap smears in last 10 years
Hysterectomy for benign lesion
Original Squamous Epithelium
Vagina and outer ectocervix
4 cell layers
Well-glycogenated (pink) unless atrophic
Columnar Epithelium
Upper and middle endo-cervical canal
Single layer of columnar cells arranged in folds
Mucin producing (not true glands)
Squamous Metaplasia
Central ectocervix and lower endocervical canal
Replacement of columnar cells by squamous epithelium
Progressive and stimulated by
Acidic environment with onset of puberty
Estrogen causing eversion of endocervix
Original Squamo-columnar Junction
Placement determined between 18-20 weeks gestation
Most often found on ectocervix
Can be found in vagina or vaginal fornices
Less apparent over time with maturation of epithelium
“New” Squamo-columnar Junction
Border between squamous epithelium and columnar
epithelium
Found on ecto-cervix or in endo-cervical canal
Majority of cervical cancers and precursor lesions
arise in immature squamous metaplasia, i.e. the
leading edge of the squamo-columnar junction
Transformation Zone
Zone between original squamo-columnar junction
and the “new” squamo-columnar junction
Nabothian cysts visually identify the transformation
zone if present
Squamous Epithelium
Parabasal Cells
Intermediate Cells
Superficial Cells
Endocervix
Endocervical Cells
TechniqueVisualize entire cervix if possibleCarefully remove any obscuring
dischargeSample ectocervix first with spatulaSample endocervix with gentle
cytobrush rotationApply material uniformly to slideFix rapidly with spray or liquid fixative
Classification of Pap smearClass Reagen(WHO) Ruchart Bethesda
Class 1 negative negative Within normal
Class 2 inflammation ------ ASCUS
Class 3 Mild dysplasia CIN-l (HPV) LSIL (HPV)
Class 4 Mod dysplasiaSeve dysplasiaCarcinoma in situ
CIN-llCIN-lll
HSIL
Class 5 Invasive cancer Invasive cancer Invasive cancer
“Normal” Pap SmearNegative for intraepithelial lesion or
malignancyOther non-neoplastic findings
Reactive cellular changes Glandular cells status post
hysterectomyAtrophy
OtherEndometrial cells (women 40 yrs)
Normal smear
Epithelial Cell Abnormalities: Squamous
Atypical squamous cellsASC-US: undetermined significanceASC-H: cannot exclude HSIL
LSIL: low grade (CIN 1)HSIL: high grade (CIN 2 - 3)Squamous cell carcinoma
SIL and CIN
Various types of cervical lesions as seen on Pap smears:
CIN I.
Various types of cervical lesions as seen on Pap smears:
CIN Il
Various types of cervical lesions as seen on Pap smears:
CIN lll
Various types of cervical lesions as seen on Pap smears:
invasive squamous cell carcinoma.
Epithelial Cell Abnormalities: Glandular
Atypical glandular cells,specify site of origin,if possible
Atypical glandular cells - favor neoplastiaEndocervical adenocarcinoma in situAdenocarcinoma
Various types of cervical lesions as seen on Pap smears:
adenocarcinoma
AccuracySingle pap smear-diagnostic sensitivity 60%False negative results upto25% due to: too scanty,too thick,too bloody,poorly
stained smear misinterpretation by the cytologist• In the presence of infection repeat cytology
has to be done after the infection is controlled
Abnormal cytology is an indication of colposcopic evaluation and directed biopsy