Vulvar cancer is usually a squamous cell skin cancer, most often occurring in elderly women. It usually manifests as a palpable lesion. Diagnosis is by biopsy. Treatment typically includes excision and lymph node dissection or sentinel lymph node mapping.
Vulvar cancer is the 4th most common gynecologic cancer in the US; it accounts for 5% of cancers of the female genital tract. Vulvar cancer caused an estimated 5950 new cases and 1110 deaths in 2016.
Average age at diagnosis is about 70, and incidence increases with age. Incidence of vulvar cancer appears to be increasing in young women.
Risk factors for vulvar cancer include vulvar intraepithelial neoplasia (VIN), human papillomavirus infection, heavy cigarette smoking, lichen sclerosus, squamous hyperplasia, squamous carcinoma of the vagina or cervix, and chronic granulomatous diseases.
VIN is a precursor to vulvar cancer. VIN may be multifocal. Sometimes adenocarcinoma of the vulva, breast, or Bartholin glands also develops.
About 90% of vulvar cancers are squamous cell carcinomas; about 5% are melanomas. Others include adenocarcinomas and transitional cell, adenoid cystic, and adenosquamous carcinomas; all may originate in Bartholin glands. Sarcomas and basal cell carcinomas with underlying adenocarcinoma also occur.
Vulvar cancer may spread as follows:
Most patients with vulvar cancer present with a palpable vulvar lesion, frequently noticed by the woman or by a clinician during pelvic examination. Women often have a long history of pruritus. They may not present until cancer is advanced. The lesion may become necrotic or ulcerated, sometimes resulting in bleeding or a watery vaginal discharge. Melanomas may appear bluish black, pigmented, or papillary.
Vulvar cancer may mimic sexually transmitted genital ulcers (chancroid), basal cell carcinoma, vulvar Paget disease (a pale eczematoid lesion), Bartholin gland cyst, or condyloma acuminatum. Clinicians should consider vulvar cancer if a vulvar lesion develops in women at low risk of sexually transmitted diseases (STDs) or if it does not respond to treatment for STDs.
A dermal punch biopsy using a local anesthetic is usually diagnostic. Occasionally, wide local excision is necessary to differentiate VIN from cancer. Subtle lesions may be delineated by staining the vulva with toluidine blue or by using colposcopy.
Staging of vulvar cancer is based on tumor size and location and on regional lymph node spread as determined by lymph node dissection done as part of initial surgical treatment (see Table: Vulvar Cancer by Stage).
Vulvar Cancer by Stage
Wide (≥ 2-cm margin) radical excision of the local tumor is indicated in all cases. Lymph node dissection can be done when stromal invasion is > 1 mm but is unnecessary when stromal invasion is < 1 mm. Radical vulvectomy is usually reserved for Bartholin gland adenocarcinoma.
Sentinel lymph node biopsy is a reasonable alternative to lymph node dissection for some women with squamous cell vulvar carcinoma. Sentinel lymph node mapping should not be considered if clinical findings suggest cancer has spread to lymph nodes in the groin. For sentinel lymph node mapping, a tracer (blue dye, technetium-99 [99Tc], indocyanine green [ICG]) is injected intradermally around and in front of the leading edge of the vulvar carcinoma.
For lateralized lesions ≤ 2 cm, unilateral wide local excision and unilateral sentinel lymph node dissection is recommended. Lesions near the midline and most lesions > 2 cm require bilateral sentinel lymph node dissection.
For stage III, lymph node dissection followed by postoperative external beam radiation therapy, often with chemotherapy (eg, 5-fluorouracil, cisplatin), is usually done before wide radical excision. The alternative is more radical or exenterative surgery.
For stage IV, treatment is some combination of pelvic exenteration, radiation therapy, and systemic chemotherapy.
Most vulvar cancers are skin cancers (eg, squamous cell carcinoma, melanoma).
Consider vulvar cancers if vulvar lesions, including pruritic lesions and ulcers, do not respond to treatment for STDs or occur in women at low risk of STDs.
Diagnose vulvar cancer by biopsy, and stage it surgically.
For cancers without distant metastases, use wide excision, and unless stromal invasion is < 1 mm, do lymph node dissection or sentinel lymph node biopsy.