Primary vaginal carcinoma is rare and comprises only 1 to 2 percent of all gynecologic malignancies (National Cancer Institute, 2011). This low incidence reflects the infrequency with which primary carcinoma arises in the vagina as well as the strict criteria for its diagnosis. According to International Federation of Gynecology and Obstetrics (FIGO) staging criteria, a lesion in the vagina that involves adjacent organs such as the cervix or vulva is, by convention, deemed primary cervical or vulvar, respectively (Pecorelli, 1999). Cancer found in the vagina is more likely to be metastatic disease than primary disease. Of these, cancers from the cervix, endometrium, and colon/rectum are the most frequent. The most common histologic type of primary vaginal cancer is squamous cell carcinoma, followed by adenocarcinoma (Platz, 1995).
Embryologically, both the müllerian ducts and the urogenital sinus contribute to form the vagina (Fig. 18-5). Early in fetal development, the caudal ends of the müllerian ducts fuse to form the uterovaginal canal, which is lined by columnar epithelium. Subsequently, squamous cells from the urogenital sinus migrate along the uterovaginal canal and replace this original columnar epithelium. These squamous cells stratify, and the vagina begins to mature and thicken. Underlying this epithelium, muscularis and adventitial layers are found.
Vascular and Lymphatic Supply
Local extension and lymphatic invasion are common patterns of vaginal cancer spread. The lymphatic channels that drain the vagina form extensive, complex, and variable anastomoses. As a result, any node in the pelvis, groin, or anorectal area may drain any part of the vagina. Of these, the external, internal, and common iliac lymph nodes are the primary sites of vaginal lymphatic drainage. Alternatively, the posterior vagina may drain to the inferior gluteal, presacral, or perirectal lymph nodes, and the distal third of the vagina may drain to the superficial and deep inguinal lymph nodes (Frank, 2005).
Hematogenous spread of vaginal cancer is less frequent, and venous drainage consists of the uterine, pudendal, and rectal veins, which drain into the internal iliac vein. Arterial blood supply to the vagina comes primarily from branches of the internal iliac artery, which include the uterine, vaginal, middle rectal, and internal pudendal arteries (Fig. 38-12).
In 2011, it is estimated that 2570 new cases of vaginal cancer will be diagnosed in the United States, and there will be 780 deaths (Siegel, 2011). The overall incidence is 0.45 cases per 100,000 women, but notably lower in whites (0.42) compared with black and Hispanic women (0.73 and 0.56, respectively) (Watson, 2009).
Rates of vaginal cancer increase with age and peak among women ≥80 years. The median age at diagnosis is 58 (Watson, 2009). Of the histologic forms of vaginal cancer, squamous cell carcinoma accounts for 70 to 80 percent of all primary cases ...