Precancerous lesions and carcinoma of the vulva
How vulval squamous cell carcinoma arises by two routes, high-risk HPV through vulval HSIL or lichen sclerosus through differentiated VIN, and spreads stepwise to the groin nodes.
By the end, you can
- Relate the skin and mucosa of the vulva to the tumours that arise from them and to their lymphatic drainage.
- Contrast the HPV-associated and HPV-independent pathways to vulval squamous cell carcinoma, including their causes, patients and molecular changes.
- Distinguish vulval HSIL (usual-type VIN) from differentiated VIN in appearance and behaviour.
- Describe keratinising and basaloid or warty carcinomas and explain why depth of invasion and groin nodes matter.
- Relate itch, skin change, ulceration and groin lumps to the stage of disease that causes them.
- Recognise the classic appearances of VIN, lichen sclerosus and extramammary Paget disease, the FIGO stages and the tests used, and explain how topical, surgical and radiation treatments act on the mechanism.
What it is
About nine in ten vulval cancers are squamous cell carcinomas. They arise by two routes, each with its own precursor: HPV-associated, driven by persistent high-risk human papillomavirus through vulval HSIL (formerly usual-type VIN), and HPV-independent, arising in skin scarred by lichen sclerosus through differentiated VIN, usually with TP53 mutation. Melanoma, basal cell carcinoma, Paget disease and gland carcinomas are much rarer.
3 types to tell apart
- HPV-associated: vulval HSIL and carcinoma
- Younger women on average; high-risk HPV, mostly type 16; often multifocal with other lower genital tract lesions. Precursor: vulval HSIL (usual-type VIN, VIN 2 and 3). Typical tumours: basaloid and warty carcinomas, with block p16 staining.
- HPV-independent: differentiated VIN and carcinoma
- The commoner route, mainly in older women with lichen sclerosus. Precursor: differentiated VIN, with subtle basal atypia and abnormal p53. Typical tumours: keratinising squamous carcinoma and the rare verrucous carcinoma.
- Non-squamous tumours
- Melanoma (the second commonest vulval cancer), basal cell carcinoma, extramammary Paget disease, Bartholin gland carcinoma and sarcomas.
US spelling: tumours → tumors.
Normal function
Skin and mucosa of the vulva
The vulva comprises the , the and , the under its , and the , which holds the and openings. The labia majora are hair-bearing keratinised skin with sweat, sebaceous and apocrine glands; the labia minora are thinner and hairless; the vestibule is lined by non-keratinising squamous mucosa and receives the ducts of the Bartholin glands.
Almost the whole surface is stratified squamous epithelium, so almost all vulval cancers are squamous cell carcinomas. Melanocytes, the basal cells of the epidermis, the glands and the connective tissue give rise to rarer tumours. Beneath the epithelium, the dermis is rich in lymphatics and small vessels.
Lymph drains first to the superficial inguinal nodes, then to the deep inguinal (femoral) nodes beside the femoral vein, and from there to the pelvic nodes. A lateral area drains mainly to the groin on its own side; the clitoris, the front of the labia minora and the , at or near the midline, drain to both groins.
| Feature | Benign or precursor | Malignant |
|---|---|---|
| Squamous epithelium | Condyloma (HPV 6, 11); vulval HSIL; differentiated VIN | Squamous cell carcinoma: about 90% |
| Melanocytes | Naevus, melanosis | Melanoma: the second commonest |
| Epidermal basal cells | None common | Basal cell carcinoma |
| Glands (Bartholin, apocrine) | Bartholin cyst; hidradenoma papilliferum | Extramammary Paget disease; Bartholin gland carcinoma |
| Connective tissue | Lipoma, fibroma | Sarcomas (rare) |
Simplified from the WHO classification (5th edition); extramammary Paget disease is an adenocarcinoma usually confined to the epidermis.
Underlying change · Step 1 of 5
Two routes: lichen sclerosus or high-risk HPV
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Underlying change · Step 2 of 5
Vulval HSIL and differentiated VIN
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Disrupted function · Step 3 of 5
Invasive squamous cell carcinoma
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Disrupted function · Step 4 of 5
Local growth and the groin nodes
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Consequences · Step 5 of 5
Itch, skin change and a lump that does not heal
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Symptoms and signs
Symptoms, signs and findings
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Exam detail
Exam detail
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Treatment
How treatment works
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Recap
Recap
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Self-check
Check your understanding
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .