A particularly aggressive type of carcinoma is the adenosquamous carcinoma. This tumor has a number of synonyms, including cylindroma, pseudoglandular squamous cell carcinoma, adenoid squamous cell carcinoma, and adenoacanthoma of the sweat gland of Lever. The tumor has a propensity for perineural invasion, early lymph node metastasis, and local recurrence. One study noted a crude 5-year survival rate of 5.5% (1 of 18) for adenosquamous carcinoma of the vulva, compared with 62.3% (48 of 77) for patients with squamous cell carcinoma (207). Treatment should be radical vulvectomy and bilateral groin dissection. Postoperative radiation therapy may be appropriate.
Basal Cell Carcinoma Basal cell carcinomas represent about 2% of vulvar cancers. As with other basal cell carcinomas, vulvar lesions commonly appear as a “rodent ulcer” with rolled edges, although nodules and macules are other morphologic varieties that occur. Most lesions are smaller than 2 cm in diameter and are usually situated on the anterior labia majora. Giant lesions occasionally occur (208). Basal cell carcinoma usually affects postmenopausal white women and is locally aggressive. Symptoms are frequently present for a prolonged period and most often include pruritus, soreness, and irritation (209). It is diagnosed by biopsy, and radical local excision is adequate treatment (210). Metastasis to regional lymph nodes is reported but is rare (211–213). The local recurrence rate is about 10% to 20% (209,214). Basal cell carcinoma of the vulva is associated with a high incidence of antecedent or concomitant malignancies elsewhere (209). In a series of 28 women with vulvar basal cell carcinoma, 10 patients had other basal cell carcinomas, and 10 patients suffered from other primary malignancies (209).
About 3% to 5% of basal cell carcinomas contain a malignant squamous component, the so-called basosquamous carcinoma. These lesions are more aggressive and should be treated as squamous carcinomas (213). Another subtype of basal cell carcinoma is the adenoid basal cell carcinoma, which must be differentiated from the more aggressive adenoid cystic carcinoma arising in a Bartholin gland or the skin (213).
Figure 38.9 Verrucous carcinoma of the vulva. Note the exophytic hyperkeratotic papillary fronds and endophytic bulky rete pegs with smooth borders.
Verrucous Carcinoma Verrucous carcinoma is a variant of squamous cell carcinoma and has distinctive clinical and pathologic characteristics (215). Although most commonly found in the oral cavity, verrucous lesions may be found on any moist membrane composed of squamous epithelium (216). In the female genital tract, these lesions may develop on the cervix, vulva, and vagina. The cause of the lesion in the female genital tract is not fully understood, but associated HPV-6 and HPV-11 were found in some studies, whereas others find it to have no association with HPV infection (217,218). Some studies found as many as one-third of the cases to have coexisting squamous carcinoma of the vulva, underscoring the importance of careful histopathologic assessment of these tumors (219).