Vulvar Dysplasia and Colposcopy

Introduction

A. Vulvar intraepithelial neoplasia (VIN) is defined as the loss of epithelial cell maturation with associated nuclear hyperchromoses and pleomorphorism, cellular crowding and abnormal mitoses.

1. Invasive vulvar cancer has features of VIN with invasion of cells into the stroma
2. Human papilloma virus (HPV) has papillaform shapes and is covered with hyperplastic squamous epithelium that possesses hyperkeratosis and parakeratosis. Human papilloma virus is not characterized by cellular atypia, but mitosis can be present.

B. Evaluation of the vulva by gross inspection only can miss detection of acetowhite lesions or other less macroscopic lesions.

Etiology, Incidence, and Clinical Characteristics

A. VIN is part of a syndrome of multifocal epithelial changes of the anogenital tract.
B. Risk factors are similar to those for cervical dysplasia.

1. early age of sexual intercourse
2. multiple sexual partners
3. altered immune system
4. association with high risk HPV types
5. a history of smoking

C. Sturgeon et al found that from 1973-1987, there was a doubling of the annual incidence of VIN from 1.1 to 2.1/100,000 women years. White women less than 35 years of age had the greatest increase. Peak in-situ incidence shifted from women greater than 54 years to women aged 35-54.
D. Crum found that women with VIN and aged 35-55 are more likely to have previous HPV, sexual transmitted diseases (STDs), preexisting VIN, a high association with cervical neoplasia, and smoking. The opposite was true for women greater than 55 years.
E. Greater than 50% of patients presenting with vulvar dysplasia are without symptoms.
F. Of patients with symptoms, pruritis is the most common.

Diagnosis

A. The key to diagnosis of VIN is a high index of suspicion.
B. Definitive diagnosis is made by colposcopic evaluation followed by biopsy.
C. The colposcopic technique differs slightly from cervical or vaginal colposcopic exam.

1. 3-5% acetic acid must be applied 3-5 minutes in advance to allow for absorption through the keratinized surface of the vulvar skin.
2. After adequate acetic acid soaks, careful examination is performed of the vulvar folds, perineal body, and the perianal and anal regions.
3. Involved regions and planned biopsy sites should be mapped.
4. The biopsy site is infiltrated with 1-2% xylocaine.
5. Biopsy is easily attained with Keyes punch or excisional technique.

D. In the past, toluidine blue was used to stain the vulva. This nuclear stain can detect areas of superficial epithelial high-grade lesions. However, there is a high incidence of false positive results, especially at excoriated or erosive sites.

Vulvar Lesions

A. White lesions

1. Leukoplakia, lesions that are white prior to application of acetic acid, come from a thick hyperkeratotic layer on the epithelial surface.
2. Acetowhite lesions with irregular geographic borders can represent flat condyloma, VIN, or prolonged application of acetic acid on normal vulva. The more intense, irregular, and raised the change, the more likely it is to be associated with HPV or dysplasia.

B. Red lesions

1. Occur in the absence of a hyperkeratotic layer.
2. Nuclei are retained through to the epithelial surface -- parakeratosis.
3. Paget's disease is a classic example of this change. Its appearance is frequently multifocal red lesions with islands of white hyperkeratotic epithelium on the surface.
4. Ulcerative lesions also may be red in appearance. These lesions may herald an invasive malignancy.

C. Pigmented lesions occur because of rapid epithelial proliferation.

1. The pigmentation is carried from the basal layer to the surface.
2. Condyloma can exhibit a surface pigmentation change.
3. More commonly, pigmentation is associated with dysplastic, multifocal vulvar, or perianal/anal lesions.

D. Vascular patterns are not common on the vulva secondary to the increased keratin layer. Punctation occasionally occurs on the mucosal surfaces of the vestibule and labia minora.

Summary

Colposcopy is particularly helpful in the diagnosis of VIN and invasive cancer. VIN associated with HPV is more frequent in younger women, less likely to be invasive, and more often multifocal. White, red, and hyperpigmented lesions are associated with VIN and vulvar cancer. Biopsy is required for definitive diagnosis.