Table 38.1 Types of Vulvar Cancer cancer of the vulva, reported at 2.5% to 7.2% with a median follow-up of 4.7 to 6.2 years (18–20). Supportive evidence that some of these lesions could be precancerous comes from molecular studies that demonstrate aneuploid DNA content, p53 overexpression, high Ki67 expression, indicating high proliferation indices and monoclonal expansion of keratinocytes in lichen sclerosus and associated squamous hyperplasia (21–23). An area of active research explores whether treatment of lichen sclerosus with superpotent topical steroids can impact the malignancy risk (18–20). Some studies reported vulvar cancer to be more common in patients who are obese, have hypertension and diabetes mellitus, or are nulliparous, but a case-control study of vulvar cancer did not confirm any of these as risk factors (15,24,25).
Types of Invasive Vulvar Cancer
The histologic subtypes of invasive vulvar cancer are shown in Table 38.1.
Approximately 90% to 92% of all invasive vulvar cancers are of the squamous cell type.
Squamous carcinomas of the vulva can be divided into distinct histologic subtypes designated as basaloid carcinoma, warty carcinoma, and keratinizing squamous carcinoma (16). Mitoses are noted in these malignancies, but atypical keratinization is the histologic hallmark of invasive vulvar cancer (26). Most vulvar squamous carcinomas reveal keratinization (Fig. 38.1). Histologic features that correlate with the occurrence of inguinal lymph node metastasis are lymph–vascular space invasion, tumor thickness, depth of stromal invasion, histologic pattern of invasion (spray and stellate versus broad and pushing), and increased amount of keratin (27–30).
Microinvasive carcinoma of the vulva (T1a) is defined as a lesion 2 cm or less in diameter with 1 mm or less stromal invasion (31). Depth of stromal invasion is measured vertically from the epithelial–stromal junction (basement membrane) of the adjacent most superficial dermal papilla to the deepest point of tumor invasion (Fig. 38.2). When the tumor invades 1 mm or less, metastasis to the inguinal lymph nodes is extremely rare among reported series. When invasion is greater than 1 mm, there is a significant risk of inguinal lymph node metastasis.
Figure 38.1 Squamous cell carcinoma of the vulva, keratinizing type. The multiple pearl formations consist of laminated keratin.
Figure 38.2 Early invasive carcinoma of vulva originating from vulvar intraepithelial neoplasia. An irregular nest of malignant cells extend from the base of rete pegs. Desmoplastic stromal reaction and chronic inﬂammation are useful diagnostic signs of stromal invasion. The depth of stromal invasion is measured from the base of the most superficial dermal papilla vertically to the deepest tumor cells.
Most patients are asymptomatic at the time of diagnosis. If symptoms exist, vulvar pruritus, a lump, or a mass are the most common findings. Less frequent symptoms include a bleeding or ulcerative lesion, discharge, pain, or dysuria. Occasionally, a large metastatic mass in the groin is the initial symptom.
A careful inspection of the vulva should be part of every gynecologic examination. On physical examination, vulvar carcinoma is usually raised and may be ﬂeshy, ulcerated, plaquelike or warty in appearance. It may be pigmented, red or white, and tender or painless. The lesion may be clinically indistinct, especially in the presence of VIN or vulvar dystrophies (12). Any lesion of the vulva warrants a biopsy.