When and How to Biopsy Vulvovaginal Skin Conditions

Dermoscopy of a vulval mucosal melanoma | Image credit: DermNet

“If you are ever concerned about cancer, just biopsy. You don't want to be the only person to have looked at that woman's vulva in a year or 5 years and miss a cancer,” said Audrey Rutherford, MD, during her session on vulvovaginal dermatology at the 2024 Society of Dermatology Physician Associates (SDPA) Fall Conference in Las Vegas, Nevada.¹

Rutherford, a board-certified dermatologist at Dermatology and Aesthetics Center of Utah in Centerville, presented cases, tips, treatment recommendations, and relevant studies to attendees to help enhance their understanding of often underdiagnosed vulvar skin disorders to help improve patient outcomes. She stressed to attendees that the sub-specialty of vulvovaginal dermatology is needed for patient care because most women do not examine their vulvas (even when symptomatic), most dermatologists do not examine their patients’ vulvas, and most gynecologists have not been thoroughly trained in dermatology care.

One of the main topics of Rutherford’s session was recognizing what to biopsy and why. When considering whether to biopsy in vulvovaginal cases, Rutherford first decides if cancer is a concern. If Rutherford has any concerns about cancerous lesions, she prefers to biopsy rather than not and miss a diagnosis such as squamous cell carcinoma.

Potential indicators of vulvar cancer that warrant biopsying include the “ugly duckling” appearance, non-healing areas, treatment-resistant concerns, and areas of induration. According to Rutherford, biopsies are not always necessary to make a non-cancer diagnosis, however, clinicians shouldn’t be afraid to biopsy the vulva.

Non-cancerous reasons to consider a vulvar biopsy include an unclear diagnosis, skin that is not responding to treatment, atypical presentation such as vessels, pigment, or texture, and blistering/erosive disease.

If a biopsy is needed, Rutherford reviewed 2 ideal options: punch biopsy and suture-assisted biopsy. She noted that punch biopsies are ideal for depth on conditions such as squamous cell carcinoma or HPV-independent vulvar intraepithelial neoplasia. Suture-assisted biopsies can have variable depth but can be used for most non-cancerous concerns.

Rutherford’s key biopsy tips include:

• Avoid the midline, including the clitoris, urethra, and anus
• Biopsy each morphologically distinct area
• Apply topical numbing cream before, keeping in mind the differences in efficacy timing on non-hair-bearing areas and hair-bearing areas
• Recommend using Vaseline and pads for care afterward and not bandages

Regarding pathology, Rutherford noted that it’s extremely important to give as much information as possible to pathologists for the best chance at an accurate and quick diagnosis.

A vulval squamous cell carcinoma arising on vulval lichen sclerosus | Image credit: DermNet

“You want to be very specific on where your biopsying, what the lesion looks like, what prior treatments have been done, what prior diagnoses have been given, and what your concerns are. I'm a little bit biased on this, but sometimes whenever you're going through the EMR and you're clicking on the body and it pops up ‘vulva’ or ‘vagina,’ that pathology will then be scooped in with the gynecologic pathology,” said Rutherford.

She added, “Sometimes that can be more challenging for pathologists who might not be as familiar with the dermatologic conditions of the vulva. If you get a non-specific condition that is chronic inflammation with no signs of malignancy...I would recommend having a dermatopathologist read that and see if there's something more specific that they can get you on diagnosis.”

Rutherford also explained to attendees her 2mm method comparison. When performing vulvar biopsies, it’s crucial to recognize the significant difference between 2mm on the skin and 2mm under the microscope. While an additional 2mm in excision might not substantially impact healing time or scarring, it can be critical in ensuring an accurate histological diagnosis. If a patient is already undergoing the discomfort and recovery associated with a biopsy, it’s essential to provide the pathologist with sufficient tissue to make a definitive diagnosis.

According to Rutherford, clinicians should strive to balance patient care with diagnostic utility—which doesn’t mean over-biopsying, but rather ensuring an adequate sample. As a guideline, Rutherford avoids taking less than a 3mm sample to optimize diagnostic outcomes.

Take-home Tips

Overall, Rutherford emphasized that if cancer is a concern, clinicians should biopsy rather than risk overlooking malignancies such as squamous cell carcinoma. She discussed key biopsy indications, techniques, and tips, including avoiding midline structures and ensuring samples are large enough—at least 3mm—to provide pathologists with adequate tissue for accurate diagnoses. Rutherford also noted the importance of detailed communication with pathologists, including lesion descriptions and prior treatments, to improve diagnostic accuracy. She urged clinicians not to hesitate with biopsies, even for non-cancerous concerns, as they can clarify unclear diagnoses or guide treatment for atypical or resistant conditions.

Reference

1. Rutherford A. Vulvovaginal dermatology. Presented at: 2024 Society of Dermatology Physician Associates Fall Conference; November 16, 2024; Las Vegas, NV.