Basic Professional Training Program for Associate Medical Technologist

Transcription

1 Basic Professional Training Program for Associate Medical Technologist Basic Cytology Part 2 (Preparartion and normal morphology) Normal Morphology in Liquid based Gynecologic Cytology Speaker: Mr. Fung Hok Mun, Simon MT/ic Cytology Lab, UCH 1 2 Ectocervix covered by non keratinising squamous mucosa. Continuous with vaginal epithelium. Proximal, joins lining of endocervix at or near the external Os. 3 4

2 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. 5 6 Point where ectocervix squamous epithelium & endocervical canal epithelium meet = SquamoColumnar Junction Changes in this area are of crucial significance in cervical pathology. 7 8

3 9 10 SquamoColumnar Junction & Transformation Zone 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 ) Squamous Metaplasia 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 puberty

4 Structure of Stratified Squamous Epithelium Structure of Stratified Squamous Epithelium 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. 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 Normal Cellular Components Superficial cells Intermediate cells Parabasal cells Squamous metaplastic cells (mature vs, immature) Endocervical cells Inflammatory cells +/ Basal cells/ reserve cells +/ Endometrial cells 15 16

5 Cytology Epithelial Cells 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 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 chromatin pattern

6 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 of inflammation or oestrogen deficiency 23 24

7 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. INTERMEDIATE Cells Tight groups or discrete depend upon hormonal state for 14 days. In 2 nd half of cycle, ragged cytoplasm may disintegrate > bare nuclei. With high progesterone, accumulate glycogen an irregular central deposit of pale yellow stained materal INTERMEDIATE Squamous Cells Nuclear diameter: 5 6 micron in diameter Mean nuclear area: 36 um

8 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 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

9 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 > picketfence. Cyanophilic cytoplasm translucent or vacuolated prone to degeneration. Fine chromation pattern; one or more small nucleoli may be identified

10 Endocervical cells 2 Occas. pink cilia are visible more common PM Mucin secreting goblet cells infrequent usually reactive feature. 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

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12 Metaplastic Cells 1 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. Polymorphs often in endometrial clusters

13 Endometrial Cells Mean nuclear area: 37 um

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16 Assessment of Squamous Cellularity Requires > 5,000 well visualized & wellpreserved 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 Obscuring Inflammation Liquid based preparations with 5,000 20,000 squamous cells Specify if 50 75% of squamous cells obscured Considered as unsatisfactory if > 75 % squamous cells obscured 63 64

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