Vulvar cancers comprise only about 4 percent of all gynecologic malignancies. Most vulvar cancers are diagnosed at an early stage (I and II). Advanced disease is found mainly in older women, perhaps due to clinical and behavioral barriers that lead to diagnostic delays. Thus, biopsy of any abnormal vulvar lesion is imperative to help diagnose this cancer early.
In the United States, vulvar cancers carry a comparatively good prognosis with a 5-year relative survival rate of 78 percent (Stroup, 2008). For resectable disease, traditional therapy includes radical excision of the vulva plus inguinal lymphadenectomy or plus sentinel lymph node biopsy. For advanced stages, chemoradiation may be used either primarily or as an adjunct to surgery to aid tumor control. All of these treatments can result in extensive short- and long-term morbidity and dramatic anatomic and functional deformity. Accordingly, vulvar cancer management recently has trended toward more conservative surgery that preserves oncologic outcome, lessens morbidity, and improves psychosexual well-being.
The vulva includes the mons pubis, labia majora and minora, clitoris, vestibule, vestibular bulbs, Bartholin glands, lesser vestibular glands, paraurethral glands, and the urethral and vaginal openings. Lateral margins of the vulva are the labiocrural folds (Fig. 38-25). Vulvar cancer may involve any of these external structures and typically arises within the covering squamous epithelium. Unlike the cervix, the vulva lacks an identifiable transformation zone. That said, squamous neoplasia arises predominantly on the vestibule at the border between the vulvar keratinized stratified squamous epithelium, which lies laterally, and the nonkeratinized squamous mucosa, which lies medially. This demarcation line is termed Hart line.
Deep to the vulva are the superficial and deep urogenital triangle compartments. The superficial space lies between Colles fascia (superficial perineal fascia) and the perineal membrane (deep perineal fascia) (Fig. 38-26). Within this space lie the ischiocavernosus, bulbospongiosus, and transverse perineal muscles and the highly vascular vestibular bulb and clitoral crus. During radical vulvectomy, dissection is carried to the depth of the perineal membrane. As a result, contents of this superficial urogenital triangle compartment that lie beneath the mass are removed during tumor excision.
The lymphatics of the vulva and distal third of the vagina typically drain into the superficial inguinal node group (Fig. 38-29). From here, lymph travels through the deep femoral lymphatics and the node of Cloquet to the pelvic nodal groups. Importantly, lymph can also drain directly from the clitoris and upper labia to the deep femoral nodes (Way, 1948). Vulvar lymphatics cross at the mons pubis and the posterior fourchette but do not cross the labiocrural folds (Morley, 1976). Thus, lesions found within 2 cm of the midline may spread to lymph nodes on either side. In contrast, lateral lesions rarely send metastases to contralateral nodes. This anatomy point influences the decision for ipsilateral or bilateral node dissection, ...