4. Cervix Flashcards
Epidemiology of cervical cancer
Peak incidence: 35–44 years of age
Etiology for cervical cancer
Human papillomavirus virus (HPV) infection
- Infection with high-risk HPV types is the main cause of cervical cancer (DNA of HPV 16 and/or 18 is found in 70% of all patients with cervical carcinoma)
- The major high-risk HPV types are HPV 16 (most common in squamous cell carcinoma) and HPV 18 (most common in adenocarcinoma)
Risk factors for cervical cancer
- Associated with HPV infection
- Multiple sexual partners (strongest risk factor)
- Early-onset of sexual activity
- Multiparity
- Immunosuppression (e.g., HIV infection, post-transplantation)
- History of sexually transmitted infections (e.g., herpes simplex, chlamydia) - Environmental risk factors
- Cigarette smoking and/or exposure to second-hand smoke (for squamous cell cancer types only)
- In-utero exposure to diethylstilbestrol (DES)
Clinical features of cervical cancer
Usually asymptomatic in the early stages
Early symptoms:
- Abnormal vaginal bleeding: irregular vaginal bleeding, heavy, irregular menstrual bleeding, postcoital spotting
- Abnormal vaginal discharge: blood-stained or purulent malodorous discharge (not necessarily accompanied by pruritus)
- Dyspareunia
- Pelvic pain
Late symptoms:
- Hydronephrosis
- Lymphedema
- Fistula formation
Cervical cancer screening
Pap smear
Definition of cervical intraepithelial neoplasia
- Precursor lesion characterized by epithelial dysplasia that begins at the basal layer of the squamocolumnar junction and extends outward
- May progress to invasive carcinoma if left untreated
Classification of cervical intraepithelial neoplasia
CIN I: mild dysplasia, involves ∼ ⅓ of the basal epithelium
- Koilocytes may be present
i. Epithelial cells with perinuclear halos
ii. Pathognomonic for HPV infection
- CIN II: moderate dysplasia, involves ⅓–⅔ of basal epithelium
- CIN III: severe, irreversible dysplasia or carcinoma in situ, involves > ⅔ of basal epithelium
Definition of invasive cervical cancer
- Characterised by invasion beyond the basement membrane of the cervical epithelium
- Cervical carcinoma most commonly arises from metaplastic squamous cell epithelium in the transformation zone
Classification of invasive cervical cancer
Squamous cell carcinoma: ∼ 80% of cases
- Subtypes include large cell keratinizing, large cell nonkeratinizing, and papillary squamous cell carcinoma.
- Irregular cell morphology
- Hyperchromatic cells with nonspherical nuclei, mitotic activity, and prominent nucleoli
- Loss of basal membrane
Adenocarcinoma: ∼ 20% of cases
- Subtypes include mucinous, endometrioid, clear-cell, and serous adenocarcinoma
- The most common is the endocervical mucinous subtype
- Atypical columnar epithelium with elongated nuclei
Small-cell carcinoma: ∼ 2% of cases
Modes of spread of invasive cervical cancer
- Direct local invasion
- Uterus, vagina
- Bladder, rectum (fistulas) - Lymphatics
- Hematogenous
- Lung, liver, bone, brain