Cancers of the vulva are uncommon and constitute only 6 percent of all gynecologic malignancies. Most vulvar cancers are diagnosed in older women. Early-stage vulvar cancers are highly curable, and thus biopsy of any abnormal vulvar lesion is imperative to help diagnose this cancer expeditiously.
The Surveillance, Epidemiology, and End Results Program (SEER) provides online survival and incidence trends for cancers in the United States. SEER (2018) data from 2008 to 2014 show vulvar cancers carry a 5-year relative survival rate of 71 percent. Historically, treatment of vulvar cancer resulted in extensive short- and long-term morbidity, with dramatic anatomic and functional deformity. Surgery is now more conservative yet preserves oncologic efficacy. For unresectable, locally advanced disease, chemoradiation may be used either primarily or as an adjunct to surgery to aid tumor control.
The external 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. 38-26, p. 815). Vulvar cancer may involve any of these external structures and typically arises within the covering squamous epithelium. Importantly, unlike the cervix, the vulva lacks an identifiable transformation zone. However, the Hart line on the vestibule marks the border between the vulvar keratinized squamous epithelium, which lies laterally, and the nonkeratinized squamous mucosa, which lies medially. Vulvar squamous neoplasia arises predominantly along the Hart line.
Deep to the external 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 p. 815). 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. 38-31, p. 819). 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 either lymph node. In contrast, lateral lesions rarely send metastases to contralateral nodes. This anatomy point influences the decision for ipsilateral or bilateral node dissection, discussed later.
The superficial inguinal nodes cluster within the femoral triangle formed by the inguinal ligament, sartorius muscle, ...