Vulvar cancer and vulvar intraepithelial neoplasia (VIN): FIGO 2021 staging, usual vs differentiated VIN, the 3-step management, sentinel node biopsy and radiotherapy

A 68-year-old woman presents with an eight-year history of vulval lichen sclerosus and a new 2 cm ulcer on the right labium majus that has not healed over three months. This is not a "lichen sclerosus flare" — it is vulvar squamous cell carcinoma until a punch biopsy proves otherwise. Your job is to biopsy the ulcer edge, stage the lesion with the FIGO 2021 system, and plan surgery built around sentinel node biopsy rather than the morbid en-bloc radical vulvectomy with bilateral inguinofemoral lymphadenectomy of a generation ago. The FIGO 2021 staging, the sentinel node evidence, and the wound-morbidity numbers are the three things an examiner wants you to defend.[1][2][4]

Overview and definition

Vulvar cancer accounts for about 4 percent of all gynaecological cancers, with about two-thirds of cases occurring in higher-income regions. The median age at diagnosis is in the mid-60s. Squamous cell carcinoma comprises over 90 percent of vulvar malignancies; the remainder include melanoma, basal cell carcinoma, Paget disease and Bartholin gland carcinoma.[1]

Vulvar cancer arises by two distinct pathogenic pathways, and recognising which pathway a patient is on changes your counselling and surveillance:[1][3]

• HPV-associated pathway — driven by high-risk HPV, producing usual-type VIN (warty/basaloid) and basaloid or warty SCC in younger women.
• HPV-independent pathway — driven by chronic lichen sclerosus inflammation, producing differentiated VIN and keratinising SCC in older women.[1]