Introduction

Squamous cell carcinoma (SCC)¹ is a malignant tumor of the epidermal keratinocytes. It is the most common and important of the malignant tumors of the vulva, accounting for 85% to 90% of cases.

Squamous cell neoplasms are classified as intraepithelial or invasive.

Epidemiology

The annual rate of vulvar SCC in the USA is about 1.7 per 100,000.²

Etiology

SCC develops in two ways: in the presence of HPV infection or in the absence of HPV.

Intraepithelial

Superficial squamous cell carcinoma is squamous cell carcinoma-in-situ (SCCIS). This is also referred to as intraepithelial neoplasia, and, on the vulva, vulvar intraepithelial neoplasia (VIN). (VIN)

Invasive

Invasive squamous cell carcinoma is an epidermal keratinocyte neoplasm that occurs as a solitary lesion on the vulva in patients older than 55 years.

The invasive lesion may occur on the background of other chronic vulvar diseases such as lichen sclerosus and lichen planus. These vulvar conditions have their own symptomatology—itching, burning, irritation, and years of dyspareunia. Of patients with lichen sclerosus, 5% develop squamous cell carcinoma of the vulva, but 30% to 40% of squamous cell carcinomas of the vulva are associated with surrounding lichen sclerosus.

Symptoms and clinical features

The lesion is usually asymptomatic but when exophytic, cracked, and ulcerated, it might bleed and can become itchy, sore, or painful. Complaints in advanced cases include discharge, dysuria, and foul odor.

Lesions of the vulva are usually unifocal and 1 to 2 cm in diameter. They may be nodular or ulcerated.

The color may vary from white to red. They are situated on the posterior fourchette, labia minora, or interlabial sulcus. As they become more exophytic and larger, the surface becomes eroded and ulcerated with varying degrees of bleeding. They may be associated with a background of lichen sclerosus in the vulva, or, more rarely, lichen planus.

Diagnosis

Diagnosis is clinical with incisional or excisional biopsy. Colposcopic examination may be of additional value.Pathology/Laboratory Findings

HPV-related lesions will show a basaloid, warty, or mixed histology while the non-HPV-related lesions are well-differentiated carcinomas with prolific keratinization and pearl formation.³ The latter may be found, histologically, in the company of lichen sclerosus or squamous cell hyperplasia.

Differential diagnosis

Differential diagnosis includes VIN, Paget disease, amelanotic melanoma, chancroid, Crohn disease, and metastatic carcinoma.

Treatment/management

Refer to a gynecologic oncologist. The tumor has to be well assessed, staged, and then specific treatment planned for tumor removal.

1. Fisher BK, Margesson, LJ. Genital Skin Disorders: Diagnosis and Treatment. Mosby, Inc., 1998. 212-214.
2. Saraiya M, Watson M, Wu X, et al. Incidence of in situ and invasive vulvar cancer in the US, 1998-2003. Cancer. 2008; 113: 2865-2872.
3. Heller DS and Wallach RC, eds. Vulvar diseases: a clinincopathological approach. 2007. Informa Healthcare, New York. 162.