What is Vulval Intraepithelial Neoplasia (VIN)? Understanding Vulvar Precancer

Vulval intraepithelial neoplasia, commonly known as VIN, is a condition where abnormal cells develop on the surface of the vulva, the external female genitalia. It’s important to understand that VIN is not vulval cancer, but rather a precancerous condition. This means that while it’s not currently cancerous, there is a possibility that it could develop into cancer over time if left untreated. The progression to cancer can take many years, and in many cases, VIN does not become cancerous.

VIN is sometimes referred to as vulvar intraepithelial neoplasia or, by some healthcare providers, as a precancer, highlighting its potential to turn into cancer. However, it’s crucial to remember that many individuals diagnosed with VIN will never develop vulval cancer.

What Factors Contribute to VIN Development?

The exact causes of VIN are not fully understood by medical professionals. However, several risk factors have been identified that can increase the likelihood of developing this condition. It’s important to note that having one or more of these risk factors does not guarantee that you will develop VIN. These factors include:

• Human Papilloma Virus (HPV) Infection: HPV is a common virus, and certain types are strongly linked to VIN.
• Smoking: Smoking is associated with an increased risk of various cancers and precancerous conditions, including VIN.
• Compromised Immune System: Conditions that weaken the immune system, such as HIV, can elevate the risk of VIN.
• Chronic Skin Conditions: Long-term vulval skin problems like lichen sclerosus are also considered risk factors for VIN.

Types of VIN: Classical and Differentiated

VIN is broadly classified into two primary types, which differ in their characteristics, causes, and potential for progression:

• Usual or Classical VIN: This is the more prevalent type of VIN. It encompasses low-grade squamous intraepithelial lesions (LSIL) and high-grade squamous intraepithelial lesions (HSIL).
• Differentiated VIN (dVIN): Differentiated VIN is less common and has distinct features compared to classical VIN.

Usual or Classical VIN: LSIL and HSIL Explained

Usual or classical VIN is frequently associated with HPV infections. Within this category, we find two sub-types that describe the extent of abnormal cell changes:

• Low-grade Squamous Intraepithelial Lesion (LSIL): Previously, LSIL was also known as VIN 1. LSIL is often linked to low-risk HPV types, which are also responsible for genital warts. These lesions are generally not cancerous and frequently resolve on their own without intervention. However, regular follow-up appointments are typically recommended to monitor for any changes.

• High-grade Squamous Intraepithelial Lesion (HSIL): HSIL, formerly referred to as VIN 2 and VIN 3, is usually caused by high-risk HPV types. Due to a higher risk of progressing to cancer, treatment is generally recommended for HSIL. Treatment options typically involve surgical procedures or topical creams. The terms LSIL and HSIL indicate how deeply the abnormal cells extend into the skin’s surface layer. If these abnormal cells penetrate the basement membrane and invade deeper tissues, the condition is then classified as vulval cancer.

Differentiated VIN (dVIN): A Less Common Variant

Differentiated VIN (dVIN) represents a less common form of VIN. It tends to occur in older women compared to HSIL and LSIL, with an average diagnosis age around 68. Unlike classical VIN, dVIN is not associated with HPV infection. It is often observed in women who have lichen sclerosus, a vulval condition characterized by inflammation, itching, and white patches on the skin.

Differentiated VIN carries a higher risk of developing into cancer compared to HSIL. Consequently, surgical intervention is often advised to prevent the potential development of vulval cancer.

Recognizing VIN Symptoms

Symptoms of VIN can vary significantly, and some individuals may experience no noticeable symptoms at all. However, when symptoms are present, they may include:

• Persistent Itching (Pruritus): This is a common symptom, often localized to the vulval area.
• Pain or Soreness: Discomfort or pain in the vulva can be experienced.
• Changes in Vulval Skin Appearance: This can include changes in color, texture, or the presence of lumps or bumps.
• Discomfort or Pain During Sexual Intercourse (Dyspareunia): Some women may experience pain or discomfort during sex.

It’s crucial to remember that these symptoms are not exclusive to VIN and can be associated with other conditions. If you experience any of these symptoms, it is essential to consult your General Practitioner (GP) for proper evaluation.

Diagnosing VIN: Tests and Procedures

If your GP suspects VIN, they will typically refer you to a specialist, usually a gynaecologist or dermatologist. The specialist will conduct an examination in a private setting, often within an outpatient clinic. The definitive diagnosis of VIN requires a tissue sample, known as a biopsy. The biopsy procedure may be performed during the initial appointment or scheduled for a later date. Before taking the biopsy, the doctor will administer a local anaesthetic to numb the vulval area, minimizing discomfort. The biopsy sample is then sent for laboratory analysis, and you will typically return to the clinic in about 2 weeks to discuss the results.

VIN Treatment Options: A Range of Approaches

The recommended treatment for VIN is tailored to several factors, including:

• Location of VIN: The specific area of the vulva affected by VIN.
• Severity of Symptoms: The extent and impact of any symptoms experienced.
• Risk of Cancer Development: The assessed likelihood of VIN progressing to vulval cancer.

In some cases, particularly for low-grade squamous intraepithelial lesion (LSIL) or VIN 1, your doctor may recommend watchful monitoring instead of immediate treatment.

However, treatment is generally advised for high-grade squamous intraepithelial lesion (HSIL) and differentiated VIN. Treatment modalities can include:

• Surgical Removal: Surgical procedures aim to remove the affected skin.
• Topical Imiquimod Cream: This cream stimulates the immune system to target and eliminate HPV and abnormal cells.
• Laser Treatment: In some instances, laser ablation may be used to destroy abnormal cells.

Monitoring and Close Follow-up for LSIL

For LSIL, the risk of cancer development is very low. If you have LSIL without significant symptoms, you and your doctor may decide to pursue monitoring rather than immediate treatment. Regular follow-up appointments will be scheduled to closely observe for any changes that might indicate progression. Treatment can be initiated if there are signs of changes in the VIN.

Surgical Procedures for VIN

Surgery for VIN typically involves removing the affected skin. A common procedure is wide local excision, where the area of VIN and a small margin of surrounding healthy tissue are removed. In cases of more widespread VIN, a skinning vulvectomy, a more extensive surgical procedure, may be necessary.

Imiquimod Cream Therapy

Imiquimod cream is a topical treatment that works by activating the body’s immune system to fight HPV and destroy VIN cells. The cream is usually applied to the affected area once a week initially, gradually increasing to three times per week, as directed by your doctor. Treatment duration can range from 3 to 4 months. Common side effects of imiquimod cream include inflammation of the vulval skin, which can manifest as redness, soreness, itching, weeping, peeling, or cracking.

Laser Ablation for VIN

Laser treatment, also known as laser ablation, is a less frequently used option that involves using a laser to destroy abnormal cells. Typically, only a single treatment session is required. Potential side effects of laser treatment for VIN can include temporary hair loss around the vulva and changes in skin colour in the treated area.

Vulval Care and Recovery

Following VIN treatment, symptoms usually improve. Your healthcare provider will provide guidance on how to care for the sensitive skin of your vulva during the recovery period.

Long-Term Follow-up and Monitoring

Regular follow-up appointments at the hospital are essential after VIN treatment. Initially, these appointments may be scheduled every few months. If your condition remains stable, the frequency of follow-up appointments will gradually decrease. During these appointments, your doctor will examine your vulva to monitor for any signs of VIN recurrence. Long-term follow-up, often for many years, is recommended due to the potential for VIN to return after treatment. Your doctor may also advise you on self-examination techniques to routinely check your vulva between appointments. It’s crucial to promptly inform your doctor or nurse if you experience any problems or concerns between scheduled appointments, rather than waiting until your next appointment.

Coping with a VIN Diagnosis

Receiving a VIN diagnosis can be emotionally challenging. Some of the tests and treatments associated with VIN may cause physical discomfort and emotional distress. Your GP and specialist will strive to make you as comfortable as possible throughout your care. You have the option to request a chaperone to be present during any examinations or appointments. A chaperone can be a friend, family member, or a trained healthcare professional, such as a practice nurse or specialist nurse.

This information provides a comprehensive overview of vulval intraepithelial neoplasia (VIN), aiming to enhance understanding of this precancerous condition, its management, and the importance of ongoing care.