Basic Professional Training Program
for Associate Medical Technologist
Speaker: Mr. Fung Hok Mun, Simon MT/ic Cytology Lab, UCH
1
Basic
Cytology
– Part
2
(Preparartion and
normal
morphology)
2
Normal
Morphology
in
Liquid
‐
based
Gynecologic
Cytology
• Ectocervix – covered by non‐keratinising squamous mucosa.
• Continuous with vaginal epithelium.
• Proximal, joins lining of endocervix at or near
5
• Endocervical canal (protected from vaginal
pH) – retains tall columnar cell lining & layer
of reserve cells.
• Mucosa – branching crypts extending into
stroma of cervix for up to 5 mm.
6
Point
where
ectocervix squamous
epithelium
&
endocervical canal
epithelium
meet
=
SquamoColumnar Junction
Changes
in
this
area
are
of
crucial
9 10
• Endocervical eversion is followed by
progressive metaplasia of exposed mucosa
(under influence of vaginal pH) to less
specialized, more hardy squamous
epithelium
( Metaplasia = a change from one adult type
of epithelium to another )
SquamoColumnar Junction
&
Transformation
Zone
• the mature endocervical columnar
epithelium will be progressively replaced by
a squamous epithelium when the
squamocolumnar junction is everted distal
to the external os exposing the endocervical epithelium to irritation in the vagina
• This process is normal and begins around
Squamous
Metaplasia
13
• Germinal layer – single, small, regular,
undifferentiated cells – BASAL cells.
• Next layer – PARABASAL cells – immature,
crowded, two‐three deep.
• INTERMEDIATE layer – variable thickness – more cytoplasm; nuclei still show
recognizable chromatin.
Structure
of
Stratified
Squamous
Epithelium
14
• Superficial cells are actually dead or dying &
exfoliate spontaneously.
• Mucosal thickness depends on hormonal
status – all layers respond.
• Under oestrogen influence, superficial layer
develops in about four days.
Structure
of
Stratified
Squamous
Epithelium
Superficial cells Intermediate cells
Parabasal cells
Squamous metaplastic cells (mature vs,
immature)
Endocervical cells
Inflammatory cells
+/‐Basal cells/ reserve cells
+/‐Endometrial cells
Cytology
– Epithelial
Cells
17
• Pap stain : 2 components are cytoplasmic
stains:
eosin – superficial cells pink or orange light green – cytoplasm of less mature.
• Nuclei are stained by haematoxklin. • Good fixation for good staining quality
BASAL
Cells
• Small primitive cells – difficult to recognize • Rarely sampled – deep position.
• Short rows of small regular cells with sparse
green cytoplasm, oval nuclei & high N/C ratio
but chromatin pattern is fine & several
chromocentres may be present.
18
PARABASAL
Cells
• Round to oval, fairly dense green cytoplasm – although if smear not well fixed cytoplasm
may take up pinkish stain of eosin.
• Nuclei occupy about one half of cell, fine
21 22
PARABASAL
Cells
• Less mature parabasal cells – in sheets. • More mature – usually dissociate. • Usually predominate in PM smears.
• young women – postnatally during lactational amenorrhoea or under abnormal conditions
INTERMEDIATE
Cells
• Polygonal shape, larger than parabasal • Pale green cytoplasm – peripheral fold
• Cytoplasm may stain with eosin – esp. if poor
fixation – ‘eosinophilic intermediate’ • Low N / C ratio.
• Nucleus round / ovoid , fine chromatin.
25
INTERMEDIATE
Cells
• Tight groups or discrete – depend upon
hormonal state for 14 days.
• In 2nd half of cycle, ragged cytoplasm may
disintegrate > bare nuclei.
• With high progesterone, accumulate glycogen – an irregular central deposit of pale yellow
stained materal.
26
INTERMEDIATE
Squamous
Cells
• Nuclear diameter: 5‐6 micron in diameter • Mean nuclear area: 36 um2
Superficial
Cells
• Large & polygonal; pink to orange flat cytoplasm,
rarely show folding as in intermediate cells • Slightly larger than intermediate cells • Nuclei small & condensed or pyknotic • Almost always discrete compare with
intermediate cells
29
Superficial
Cells
• Granular cell layer cells show small dark blue
granules in cytoplasm.
• Nests of benign squamous cells – epithelial
pearls – sometimes seen in normal smears. • Cells may also be artefactually squashed &
distorted in smear taking.
33 34
Anucleate Squames
• Mature superficial squamous cells with loss of
nuclei.
• Polygonal shape; often stain with dimer of eosin
>> orange or yellow cytoplasm.
• Anucleate squames in combination with granular
cells > completion of ‘keratinization’ process.
Endocervical cells
‐
1
• Small sheets/ groups, less often single. • From above > honeycomb; side‐on > picket‐
fence.
• Cyanophilic cytoplasm – translucent or
vacuolated – prone to degeneration.
• Fine chromation pattern; one or more small
Endocervical cells
‐
2
• Occas. pink cilia are visible – more common PM • Mucin‐secreting goblet cells – infrequent –
usually reactive feature.
37
Endocervical cells
‐
3
• Nuclear size may vary considerably within a
group.
• Multinucleation not uncommon – esp. in
inflammation or injury.
• Smear taking method affects yield: Brush >> Aylesbury >> Ayre spatula
45
Metaplastic Cells
1
46
• Normal constituent once tranformation zone
develops
• Immature: don’t exfoliate spontaneously
• Mature: resemble original ectocervix intermediate
cells & superficial cells – so can’t recognize as
separate population
• Identifiable squamous metaplastic cells are size of
parabasal & early intermediate cells
Endometrial
Cells
2
• Early in menstruation, well‐formed, tight. 3‐D
clusters – epithelial cell rim & central stromal cell
core.
• Soon degenerative nuclear crumpling &
disorganization of cells > small clusters of densely
hyperchromatic crowded cells.
49
• Mean nuclear area: 37 um2
Endometrial
Cells
61
Assessment
of
Squamous
Cellularity
62
Requires > 5,000 well‐visualized & well‐
preserved squamous cells
‐ ThinPrep (preparation diameter = 20mm): > 3‐4 squamous cells per 40 x HPFs
‐ SurePath (preparation diameter = 13mm): > 8‐9 squamous cells per 40 x HPFs
A minimum of 10 microscopic fields should be
assessed
Low
Squamous
Cellularity
Liquid –based preparations with 5,000 –20,000 squamous cells
Obscuring
Inflammation
Specify if 50‐75% of squamous cells obscured
Considered as “unsatisfactory” if
