L1 & L2 - Pathology of the Female Reproductive Tract 1 & 2 Flashcards
What type of epithelium in vulva and vagina?
Stratified squamous epithelium
Vagina at puberty
Oestrogen secreted by the ovary stimulates maturation of squamous epithelial cells
Glycogen is formed within mature squamous epithelial cells
Glycogen in cells shed from the surface is substrate for vaginal anaerobic organisms (dominated by lactobacilli)
Lactobacilli produce lactic acid keeping vaginal pH below 4.5
3 parts of cervix
Ectocervix
Endocervix
Transformation zone
Ectocervix formed of
stratified squamous epithelium
Endocervix formed of
single layer of tall, mucin producing columnar cells
Endocervix has a large SA due to
Columnar epithelium lines tiny blind ending channels (‘clefts’)
These radiate out from the endocervical canal into the surrounding stroma
What type of epithelium lines the endocervix?
columnar epithelium
What is the junction between the ecto and endocervix called?
Squamo-columnar junction
Formation of the transformation zone
During puberty the cervix changes shape
The lips of the cervix grow
The distal end of the endocervix opens
Endocervical mucosa becomes exposed to the vaginal environment
Describe the process of squamous metaplasia (transformation zone)
The distal endocervical columnar epithelium is exposed to the acidic vaginal environment
It is not suited to this, so undergoes an adaptive change called metaplasia
Reserve cells in this area proliferate and mature to form squamous epithelium: This process is called squamous metaplasia
Define metaplasia
A transformation of cell type from one kind of mature differentiate cell type to another kind of mature differentiated cell type
Describe how the characteristics of the metaplastic squamous epithelium change over time
At first, the metaplastic squamous epithelium is thin and delicate (lots of proliferation and maturation is incomplete)
With time, the metaplastic epithelium comes to be as strong and well formed as that on the ectocervix
What is the myometrium?
Bundles of smooth muscle, vasculature and nerves
Endometrium: proliferative phase (before ovulation)
Tubular glands
Specialised stroma
Blood vessels
Mitoses in glands
Endometrium: secretory phase
Cork screw glands
Specialised stroma
Blood vessels
Secretions in glands
Define neoplasia
‘New growth’ - abnormal, uncoordinated and excessive cell growth
Persists following withdrawal of stimulus and associated with genetic alterations
Nomenclature of neoplasms
Different neoplasms have different behaviour
Accurate identification and naming therefore important for treating the patient
How are neoplasms classified?
According to their behaviour and histogenesis
Behaviour: benign or malignant
Histogenesis: recognising the cell of origin
Benign neoplasms
Remains localised and doesn’t invade surrounding tissues
Generally grow slowly
Good resemblance of parent tissue
Leiomyoma of the myometrium ‘fibroid’
A benign neoplasm of smooth muscle
Localised
Slow growing
Consequences of benign neoplasms
Pressure on adjacent tissue
Obstruction of lumen of a hollow organ
Hormone production
Transformation into a malignant neoplasm
Symptoms for the patient
Clinical problems of benign neoplasms
Pressure on adjacent tissue
-bladder (frequency) Rectosigmoid (constipation)
Obstruction to lumen of a hollow organ
-adjacent (ureters) blocking endocervix
Hormone production
-? erythropoietin producing polycythaemia
Transformation into malignant neoplasm
-probably malignancy arises de novo
Abnormal uterine bleeding, pain
Malignant neoplasms
Invade into surrounding tissues
Spread via lymphatics to lymph nodes and blood vessels to other sites (metastasis)
Generally grow relatively quickly
Variable resemblance to parent tissue
How does malignant neoplastic tissue look different to normal tissue?
Loss of differentiation
Loss of cellular cohesion
Enlarged irregular dark nuclei
Increased numbers of mitoses
Consequences of malignant neoplasms
Destruction of adjacent tissue
Metastasis
Blood loss from ulcerated surfaces
Obstruction of hollow viscera
Production of hormones
Weight loss and debility
Anxiety and pain
Histogenesis of neoplasms
Classification by cell origin
Determined by examining tissue under the microscope
Resemblance to parent tissue correlates with clinical behaviour
Suffix of neoplasms
-oma
Malignant epithelial tumours are called
carcinomas
Carcinomas are named for
the epithelial cell type which they resemble
Adenocarcinomas are
carcinomas of glandular epithelium
Malignant stromal tumours are called
sarcomas
Malignant tumour of vulva
Squamous cell carcinoma
Malignant tumour of vagina
Squamous cell carcinoma
Malignant tumour of cervix
Squamous cell carcinoma
Adenocarcinoma
Malignant tumour of endometrium
Glandular - adenocarcinoma
Stroma - stromal sarcoma
Malignant tumour of myometrium
sm muscle - leiomyosarcoma
For some malignant neoplasms a ‘pre-malignant’ state is identified
Termed dysplasia
Accumulation of cells which look somewhat like malignant cells but do not invade the basement membrane
Dysplastic lesions may (but don’t always) progress to invasive malignancy
Recognising dysplastic lesions allows early treatment before invasion occurs
Define dysplasia
Disordered growth and differentiation characterised by increases proliferation (more mitoses), atypia of cells and decreased differentiation
Dysplasia terminology for cervix
Generic: dysplasia
UK: Cervical intra-epithelial neoplasia (CIN)
US: Squamous intra-epithelial lesion (SIL)
How does the degree of neoplasia affect the likelihood of developing invasive malignancy?
E.g. CIN 1, CIN 2, CIN3
CIN3 highest percentage predicted to progress into malignancy
Dysplasia often occurs in sited where there is metaplasia. Name some sites in the body
Squamous metaplasia of the cervical transformation zone
Squamous metaplasia of the bronchial epithelium
Glandular metaplasia of the distal oesophagus
How do normal epithelium cells and dysplastic epithelium differ?
Normal surface cells have a small nucleus and lots of cytoplasm
Dysplastic cells have a higher ratio of nuclear size to cytoplasmic volume, and the nuclei show the same features that we associate with malignancy
What is the difference between dysplasia and carcinoma?
Invasion through the basement membrane
What infection causes CIN and cervical cancer?
HPV
Human Papillomavirus
HPVs infect epithelium
Confined to local site of infection without viraemia
Over 130 HPV types, some of which infect the anogenital mucosa
Double stranded DNA virus 7.9Kbp
How may HPVs be grouped?
According to risk association with malignancy
High risk HPV - 16, 18
Low risk HPV - 6, 11
How to avoid HPV
HPV vaccination
Population based screening
- cervical sample cytology
- cervical sample HPV test
Colposcopy
Treatment of high grade dysplasia
Large loop excision of the transformation zone
Where is endometrial cancer most common
North America and Europe
The incidence of cervical cancer is
decreasing
The incidence of endometrial cancer is
increasing
Explain the peaks in cervical cancer
The separate peaks in cervical cancer incidence reflect a birth cohort effect
This happens when a group of people experience different circumstances to those born immediately before or after
An increase in cervical cancer incidence and mortality was seen in women reaching the age of sexual debut during WW1 and again in WW2
Key facts about the incidence of cervical cancer
Decreased since early 1980s
Follows the intro of NHS cervical screening programme
Birth cohort effect exists, believed to reflect different exposure to HPV at time women reached age of sexual debut
HPB vaccine is creating new birth cohorts
