Vulvar cancer is a rare gynecologic cancer comprising only 5% of gynecologic malignancies. Given the low incidence of disease, many primary providers and even obstetricians and gynecologists many never encounter a case. Increased awareness of vulvar cancer and vulvar dysplasia among patients and physicians may decrease diagnostic delays and expedite patient therapy.
Diagnosis
There is a well documented delay in diagnosis of vulvar cancer that is attributed to both the patient and the physician. Patients may feel uncomfortable or embarrassed telling their physicians about vulvar symptoms and providers may not recognize the risk for malignancy and provide alternative therapies prior to biopsy (J Reprod Med. 1999;44[9]:766-8.).
Dr. Stephanie A. Sullivan
Risk factors for vulvar cancer include human papillomavirus (HPV) infection, a history of smoking, immunosuppression, and a history of an abnormal pap smear. Vulvar dystrophy, lichen sclerosis, and squamous intraepithelial lesions have also been suggested as precursor lesions of invasive cancers. The key to early diagnosis and treatment is immediate in-office biopsy.
When evaluating a patient with a vulvar lesion, the initial evaluation should include a thorough exam with a measurement of the lesion and evaluation of inguinal lymph nodes. Also, a detailed description of a lesion’s relationship to the midline (how many centimeters away) and other vital structures (clitoris, urethra, anus) is important.
An in-office biopsy can be done on initial presentation and should include the lesion in question and underlying stroma in an effort to delineate depth of invasion. While shave biopsies may be appropriate for some skin lesions, if there is any concern for malignancy, a punch biopsy is preferred.
Pathology
Squamous cell carcinoma is the most common histologic subtype (greater than 90%) followed by malignant melanoma. Malignant melanoma poses a diagnostic challenge as 25% may present with nonpigmented lesions. These lesions may arise from a junctional nevus and are more common in postmenopausal white women.
Dr. Paola A. Gehrig
The measurement of tumor thickness is essential in evaluation of melanoma. A diagnosis of vulvar melanoma should be referred to a gynecologic oncologist for further evaluation and treatment. Frequently these patients require a multidisciplinary approach with other medical and surgical subspecialties consulting.
Adenocarcinoma of the vulva frequently arises within the Bartholin glands. Bartholin gland disease is typically a disease of young women. Any abscess or lesion in the bartholin gland in women older than 50 years should raise awareness of the possibility of malignancy. Providers should have a low threshold for biopsy of any Bartholin lesion in older women and for any Bartholin gland lesion or cyst that returns or persists after initial drainage.
Staging pearls
Vulvar cancer spreads by direct extension, lymphatic embolization and hematogenous spread. Lymphatic spread can occur early in the disease and portends a much worse prognosis. In 2009, the International Federation of Gynecology and Obstetrics (FIGO) revised the staging system. The most significant change was in stage III disease, which now includes any patient with lymph node involvement. This change emphasizes lymph node status as the single most important prognostic factor. The 5-year overall survival of patients with locally advanced tumors but negative regional lymph nodes (62%) has been found to be significantly better than those with positive nodal status (39%, P value less than.0001) (Gynecol Oncol. 2008;110[1]:83-6.).
In patients with stage IA disease, which includes lesions less than 2 cm in size with stromal invasion of less than 1 mm, the risk of lymph node metastasis is low. These patients do not require inguinal lymph node dissection. If lesions are greater than 2 cm and/or have greater than 1 mm depth of invasion, a lymph node dissection is indicated. Lymph node dissection is performed on the ipsilateral side of the lesion as long as the lesion is more than 2 cm from a midline structure. If the lesion is in the midline or within 2 cm of the midline, a bilateral inguinal lymph node dissection is recommended.
There has been a recent uptake of the sentinel inguinal lymph node biopsy technique after two large prospective studies (the GROINSS V trial and GOG 173) validated this methodology (Lancet Oncol. 2010 Jul;11[7]:646-52 and Gynecol Oncol. 2013 Feb;128[2]:155-9).
Treatment
Surgical management of stage I and II disease involves a wide radical excision of the tumor with a 1-cm circumferential margin. Tumors with a depth of invasion of less than 1 mm do not require lymphadenectomy (Gynecol Oncol. 1992 Mar;44[3]:240-4). Stage I/II disease with deeper than 1-mm invasion requires a 2-cm margin and either sentinel node evaluation or lymphadenectomy. Survival for women with adequate resection of primary squamous carcinoma with negative lymph node involvement is greater than 90%.