Vulvar cancer accounts for about 3 to 4% of all gynecologic malignancies in the USA. An estimated 3,300 new cases were diagnosed in 1996. The average age at diagnosis is about 70 yr, and incidence increases with age.
Risk factors include chronic vulvar pruritus, human papillomavirus infection, vulvar dystrophy, and vulvar intraepithelial neoplasia (VIN). Patients with a history of squamous cell malignancy of the cervix or vagina have a higher incidence of vulvar cancer.
About 90% of vulvar cancers are squamous cell carcinomas, followed by melanomas (about 5%). The remainder include adenocarcinomas and transitional cell, adenoid cystic, and adenosquamous carcinomas, all of which may arise in Bartholin’s glands. Sarcomas and basal cell carcinoma with underlying adenocarcinoma also occur.
VIN is a premalignant condition of the vulva. Although it was originally considered a precursor to invasive squamous cell carcinoma of the vulva, its malignant potential is relatively low. VIN may be multifocal in location. Paget’s disease of the vulva is an eczematoid lesion characterized by large pale epidermal cells. In about 20% of the cases, VIN and Paget’s disease are associated with synchronous or metachronous adenocarcinoma in the vulva, breast, or Bartholin’s glands.
Vulvar cancer may spread by direct extension into adjacent structures (eg, urethra, bladder, vagina, perineum, anus, rectum), through lymphatic channels to the inguinal lymph nodes (embolic spread), or hematogenously. If the inguinal lymph nodes are involved, the cancer may spread to the pelvic and para-aortic lymph nodes.
Symptoms, Signs, and Diagnosis
The most common complaint is a palpable vulvar lesion. The patient often has a long history of pruritus, with or without treatment. The diagnosis is often delayed because patients do not visit a physician because of embarrassment or fear. About 20% of patients are asymptomatic, and the lesion is identified during a routine pelvic examination. If the lesion becomes necrotic or ulcerated, bleeding or a watery vaginal discharge may occur.
A simple dermal punch biopsy using a local anesthetic usually yields a definitive diagnosis of vulvar cancer. Occasionally, wide local excision is necessary to differentiate a preinvasive lesion from invasive carcinoma. Subtle lesions may be delineated by staining the vulva with toluidine blue or by using colposcopy. Differential diagnosis includes venereal diseases (granuloma inguinale, chancroid, lymphogranuloma venereum, syphilis), basal cell carcinoma (rodent ulcer), VIN, Paget’s disease, and condyloma acuminatum. Melanomas frequently appear as bluish black, pigmented, or papillary lesions.
Prognosis is related to stage of the disease, which is based on tumor size and location and regional lymph node status (
see Table 241-5). The 5-yr survival rates are > 90% for stage I, 80% for stage II, 50 to 60% for stage III, and 15% for stage IV. Risk of lymph node spread is proportional to the tumor’s size and depth of invasion.
With malignant vulvar melanomas, the risk of metastasis is high. Risk depends mostly on invasion depth but also on tumor size.
Treatment of choice is radical excision of the local tumor (often radical vulvectomy) and a unilateral or bilateral inguinal and femoral lymph node dissection. For small lesions (< 2 cm) with an invasion depth of < 1 mm, wide local excision can be used. For lateralized lesions < 2 cm, unilateral radical hemivulvectomy and unilateral inguinal femoral lymph node dissection can be used. Lesions near the midline require a bilateral inguinal femoral lymph node dissection. Lesions > 2 cm usually require a radical vulvectomy and bilateral inguinal and femoral lymph node dissection.
For locally advanced (stage III) vulvar cancers, preoperative external beam radiation therapy is used, often in conjunction with chemotherapy (eg, 5-fluorouracil, cisplatin). Usually, a bilateral inguinal femoral lymph node dissection is performed first, followed by radiation therapy, then local radical excision of the tumor or tumor bed. This combined approach can preclude ultraradical or exenterative surgery.
Revision date: June 18, 2011
Last revised: by Janet A. Staessen, MD, PhD