B27. Premalignant and malignant vulvar diseases (VAIN, VIN)
Vulvar cancer
Cancer of the vulva is mostly a disease of older (60 – 70 years) women. It’s one of the less common gynaecological cancers (5%).
The prognosis of vulvar cancer is poor, even though most are discovered in an early stage.
Squamous cell carcinoma is the most common histological type, accounting for 90% of cases. The second most common is adenocarcinoma, which originates from the Bartholin glands.
Vulvar intraepithelial neoplasia
Vulvar intraepithelial neoplasia (VIN) is the premalignant precursor to squamous cell vulvar cancer.
VIN is classified according to the WHO 2020 system. According to this system, the cells can either be:
- Low-grade VIN
- High-grade VIN
- Differentiated vulvar intraepithelial neoplasia (dVIN)
Low-grade VIN is a benign lesion and is not premalignant. High-grade VIN and dVIN are associated with the development of vulvar cancer.
High-grade VIN is associated with HPV and is the most common form of VIN. It’s also associated with smoking. These lesions are often multifocal (many foci within the same organ) and multicentric (concomitant foci in other organs, like vagina, cervix).
dVIN is not associated with HPV and has a worse prognosis than high-grade VIN. It’s associated with lichen sclerosis. These lesions are unifocal and unicentric.
FIGO classification
Not included in the topic name so I suppose it’s not important?
| Stage | Description |
|---|---|
| I | Tumor confined to the vulva and/or perineum |
| II | Tumor of any size with extension to adjacent perineal structures (distal third of the urethra, distal third of the vagina, anal involvement) |
| III | Tumour of any size with or without extension to adjacent perineal structures (1/3 lower urethra, 1/3 lower vagina, anus) with positive inguinal-femoral lymph nodes |
| IV | Tumour invades other regional (2/3 upper urethra, 2/3 upper vagina), or distant structures |
(Substages excluded for simplicity)
Clinical features
Patients with VIN or vulvar cancer usually present with a vulvar lesion, which is visible but often asymptomatic. If symptomatic, it can be itchy or bleeding.
Diagnosis and evaluation
Diagnosis is made based of biopsy of the lesion. It can be difficult to distinguish VIN from lichen sclerosus or lichen planus, so biopsy should be taken of all lesions of the vulva which are not certain to be benign.
Treatment
Low-grade VIN is not premalignant and does not require treatment unless symptomatic. High-grade VIN and dVIN can be treated by surgical excision or by ablation. Unfortunately, recurrence is common, so patients should be monitored regularly for recurrence.
The treatment of vulvar cancer is generally surgical. The radicality of the surgery depends on the stage, the age of the patient, the comorbidities, and the stages of the lymph nodes. The options are:
- Local excision with 1 cm free margin
- Partial vulvectomy
- Radical vulvectomy ± inguinofemoral lymphadenectomy ± pelvic lymphadenectomy
- Pelvic exenteration is the most radical treatment option. It involves removing all organs from the pelvic cavity. Rarely performed.
The stages of the lymph nodes should be determined by sentinel lymph node biopsy. The sentinel lymph nodes in case of vulvar cancer are called Cloquet or Rosenmüller lymph nodes. If the sentinel lymph node is positive, regional lymphadenectomy is necessary.
Radiochemotherapy may be an option in recurring or high stage cancers. In case of palliative cases, electro-excision or laser-excision may be used.
Vaginal intraepithelial neoplasia
Vaginal intraepithelial neoplasia (VAIN) is the premalignant precursor to vaginal cancer. VAIN is, like CIN and high grade VIN, associated with HPV, and is often present simultaneously as any of these (due to the multifocal and multicentric character of HPV lesions). VAIN is very rare.
It’s classified like this:
- Low grade squamous intraepithelial lesion (VAIN 1)
- High grade squamous intraepithelial lesion (VAIN 2/VAIN 3)
VAIN is usually asymptomatic. It can be screened for by Pap smear, it can be diagnosed by biopsy.
It is treated surgically or with ablation by laser.