Vulvar Intraepithelial As with the vulvar dystrophies, there is confusion regarding the nomenclature for VIN. Four Neoplasia major terms are used: erythroplasia of Queyrat, Bowen’s disease, carcinoma in situ simplex, and Paget’s disease. In 1976, the ISSVD decreed that the first three lesions were merely gross variants
Table 19.13 Classification of Epithelial Vulvar Diseases
Nonneoplastic epithelial disorders of skin and mucosa
Tumors of melanocytes, noninvasive
VIN, vulvar intraepithelial neoplasia. From Committee on Terminology, International Society for the Study of Vulvar Disease. New nomenclature for vulvar disease. Int J Gynecol Pathol 1989;8:83, with permission.
CHAPTER 19 Intraepithelial Disease of the Cervix, Vagina, and Vulva
Figure 19.19 Carcinoma in situ of the vulva (vulvar intraepithelial neoplasia grade 3, VIN 3).
of the same disease process and that all of these entities should be included under the umbrella term squamous cell carcinoma in situ (stage 0) (114). In 1986, the ISSVD recommended the term vulvar intraepithelial neoplasia (Table 19.13).
VIN is graded as 1 (mild dysplasia), 2 (moderate dysplasia), or 3 (severe dysplasia or CIS) on the basis of cellular immaturity, nuclear abnormalities, maturation disturbance, and mitotic activity. In VIN 1, immature cells, cellular disorganization, and mitotic activity occur predominantly in the lower one-third of the epithelium, whereas in VIN 3, immature cells with scanty cytoplasm and severe chromatinic alterations occupy most of the epithelium (Fig. 19.19). Dyskeratotic cells and mitotic figures occur in the superficial layer. The appearance of VIN 2 is intermediate between VIN 1 and VIN 3. Additional cytopathic changes of HPV infection, such as perinuclear halos with displacement of the nuclei by the intracytoplasmic viral protein, thickened cell borders, binucleation, and multinucleation, are common in the superficial layers of VIN, especially in VIN 1 and VIN 2. These viral changes are not definitive evidence of neoplasia but are indicative of viral exposure (140). Most vulvar condylomas are associated with HPV-6 and -11, whereas HPV-16 is detected in more than 80% of VIN cases by molecular techniques.
VIN 3 can be unifocal or multifocal. Typically, multifocal VIN 3 presents with small hyper-pigmented lesions on the labia majora (Fig. 19.20). Some cases of VIN 3 are more conﬂuent, extending to the posterior fourchette and involving the perineal tissues. The term bowenoid papulosis (bowenoid dysplasia) was used to describe multifocal VIN lesions ranging from grade 1 to 3. Clinically, patients with bowenoid papulosis present with multiple small pigmented papules (40% of cases) that are usually less than 5 mm in diameter. Most women with these lesions are in their 20s, and some are pregnant. After childbirth, the lesions may regress spontaneously. The term bowenoid papulosis is no longer recommended by the ISSVD.
Paget’s Disease of the Extramammary Paget’s disease of the vulva (AIS) was described 27 years after the description
Vulva by Sir James Paget of the mammary lesion that now bears his name (141). Some patients with vulvar Paget’s disease have an underlying adenocarcinoma, although the precise frequency is difficult to ascertain.