Gynaecological Pathology

Cervical Pathology

Cervical Intraepithelial Neoplasia (CIN)

• CIN 1: mild dysplasia, lower 1/3 of epithelium; most regress spontaneously (60%)
• CIN 2: moderate dysplasia, lower 2/3; intermediate regression/progression
• CIN 3: severe dysplasia / carcinoma in situ, full thickness; 30-50% progress to invasive cancer over 10-30 years
• HPV types: 16 and 18 cause ~70% of cervical cancers; 6 and 11 cause genital warts (NOT cancer)
• HPV vaccination: 9-valent vaccine (Gardasil 9) covers types 6, 11, 16, 18, 31, 33, 45, 52, 58

Cervical Screening (UK Programme)

• Uniform 5-yearly interval for ages 25-64 with an HPV-negative result (extended from the previous 3-yearly-under-50/5-yearly-50+ split, effective 1 July 2025 — see NHS cervical screening programme guidance)
• First invitation at age 24.5
• HPV primary screening (since 2019): HPV test first → if positive → cytology triage on the same sample; if HPV-negative, routine recall in 5 years regardless of age
• HPV-vaccinated individuals still require screening — the vaccine does not cover all oncogenic HPV subtypes
• Colposcopy: acetic acid (white areas = acetowhite = abnormal); iodine (Schiller's test: normal epithelium stains brown; abnormal does not take up iodine)

Cervical Cancer

• Squamous cell carcinoma (80%), adenocarcinoma (20%)
• FIGO staging: Stage I (confined to cervix), Stage II (beyond cervix, not to pelvic wall), Stage III (pelvic wall/lower vagina/hydronephrosis), Stage IV (bladder/rectum/distant)
• Treatment: early (IA1-IB1) — surgery; advanced — chemoradiotherapy (cisplatin-based)

Endometrial Pathology

Endometrial Hyperplasia

• Without atypia: low risk of progression to cancer (<5%); managed with progestogens (LNG-IUS first-line) or observation
• With atypia (endometrial intraepithelial neoplasia): 30-40% risk of progression or concurrent cancer; hysterectomy recommended (unless fertility desired → high-dose progestogens with close surveillance)
• Risk factors: unopposed oestrogen (obesity, PCOS, tamoxifen, oestrogen-only HRT without progestogen), nulliparity, late menopause

Endometrial Cancer

• Most common gynaecological cancer in developed countries
• Type 1 (80%): endometrioid; oestrogen-dependent; younger, obese patients; better prognosis; often preceded by hyperplasia
• Type 2 (20%): serous, clear cell; NOT oestrogen-dependent; older patients; poorer prognosis; not preceded by hyperplasia
• FIGO staging: I (confined to corpus), II (cervical stromal invasion), III (local spread: serosa, adnexa, vagina, nodes), IV (bladder/bowel mucosa or distant)
• Treatment: total hysterectomy + BSO ± lymphadenectomy ± adjuvant therapy

Ovarian Tumours

Classification

| Category | Examples | Key Features | |----------|---------|-------------| | Epithelial (60-70%) | Serous (most common), mucinous, endometrioid, clear cell, Brenner | Most common in postmenopausal; serous can be high-grade (aggressive) or low-grade | | Germ cell (15-20%) | Mature teratoma (dermoid cyst — most common benign), immature teratoma, dysgerminoma, yolk sac tumour, choriocarcinoma | Young women; dermoid: hair, teeth, fat, thyroid (struma ovarii); dysgerminoma = seminoma equivalent | | Sex cord-stromal (5-8%) | Granulosa cell tumour, fibroma, thecoma, Sertoli-Leydig cell tumour | Granulosa cell: produces oestrogen → endometrial hyperplasia/cancer; Sertoli-Leydig: virilisation |

Tumour Markers

• CA-125: epithelial ovarian cancer (not specific — elevated in endometriosis, fibroids, pregnancy, peritonitis)
• AFP: yolk sac tumour, immature teratoma
• hCG: choriocarcinoma, dysgerminoma (some)
• LDH: dysgerminoma
• Inhibin: granulosa cell tumour
• RMI (Risk of Malignancy Index): CA-125 × ultrasound score × menopausal status; RMI ≥250 → refer to cancer centre

Gestational Trophoblastic Disease (GTD)

| Type | Features | |------|----------| | Complete mole | 46,XX (all paternal origin — androgenetic); no fetal tissue; "snowstorm" USS; very high hCG; 15-20% risk of malignant transformation | | Partial mole | 69,XXX or 69,XXY (triploid); some fetal tissue present; lower hCG than complete; 0.5-5% malignancy risk | | Choriocarcinoma | Highly malignant; follows molar pregnancy (50%), miscarriage (25%), normal pregnancy (25%); haematogenous spread (lung most common); very sensitive to chemotherapy (cure rate >95%) |

• Follow-up: serial hCG monitoring through specialist centres (Charing Cross, Sheffield, Dundee)
• Advise against pregnancy until hCG normalised and follow-up complete

Vulval Pathology

• Lichen sclerosus: white atrophic plaques; itching; affects vulva perianally ("figure-of-eight"); 3-5% risk of vulval SCC; treat with potent topical steroids (clobetasol); lifelong follow-up
• VIN (vulval intraepithelial neoplasia): usual type (HPV-related, younger) vs differentiated type (non-HPV, associated with lichen sclerosus, higher malignancy risk)
• Vulval cancer: SCC most common (90%); presents as lump/ulcer; staging includes inguinal lymph node assessment; sentinel node biopsy increasingly used

Fibroids (Leiomyomas)

• Most common benign uterine tumour; oestrogen and progesterone dependent
• Types: submucosal (most symptomatic — menorrhagia), intramural, subserosal
• Degeneration types: hyaline (most common), red/carneous (in pregnancy — acute pain), cystic, calcific, sarcomatous (<0.5%)
• Treatment: medical (tranexamic acid, GnRH agonists, ulipristal), surgical (myomectomy, hysterectomy), UAE (uterine artery embolisation)

Important Facts for MRCOG

• HPV 16 and 18: cause 70% of cervical cancers; HPV 6 and 11: cause warts only
• Endometrial hyperplasia with atypia: 30-40% malignancy risk → hysterectomy recommended
• Type 1 endometrial cancer: endometrioid, oestrogen-dependent, better prognosis
• Granulosa cell tumour: produces oestrogen → endometrial hyperplasia; marker = inhibin
• Complete mole: 46,XX (all paternal); partial mole: triploid
• Choriocarcinoma: highly chemo-sensitive; cure rate >95%
• Lichen sclerosus: 3-5% risk of vulval SCC; treat with clobetasol
• Red degeneration of fibroids: occurs in pregnancy; managed conservatively

Clinically reviewed by NHS obstetricians and gynaecologists

MRCOG AI is an independent educational tool. It is not affiliated with, endorsed by, or connected to the Royal College of Obstetricians and Gynaecologists (RCOG).