3 A vulval biopsy may be performed for several reasons: to confirm the clinical diagnosis, to differentiate between clinical diagnoses when it is not possible to be certain on the basis of clinical features alone, and to aid in making a clear diagnosis where the clinical signs are atypical. A vulval biopsy should not be performed in isolation without considering the clinical signs and symptoms. Taking a biopsy and sending it to a pathologist for a diagnosis without any clinical information is dangerous as the wrong conclusions can easily be drawn. The biopsy should be accompanied by an accurate description of the clinical examination (supplied by pictures) and the clinical diagnostic hypothesis. This information is essential for the pathologist to interpret the histopathological features of vulval lesions correctly. Many vulval problems are dermatological diseases, so ideally an expert dermatopathologist should report the histology, or at least be available to discuss difficult cases. The environment of the vulva, with heat and moisture, can modify some histological features, making it more difficult to make a diagnosis. The application of topical treatment before the biopsy can alter the histopathological signs. A multidisciplinary approach involving pathologists, gynaecologists and dermatologists is fundamental to overcome possible misunderstanding and to allow for clinico‐pathological correlation. Biopsy can be incisional or excisional. In the first case, the biopsy has a specific diagnostic purpose; in the second case, it can also have a therapeutic role. The site of a biopsy must be chosen carefully. For example, it is unhelpful to biopsy the base of an ulcer or erosion because the most useful diagnostic histological features are likely to be found at the edge of the lesion. Specific issues relating to biopsy site are detailed in subsequent chapters. Before taking the biopsy, check that the patient does not have any coagulopathy or allergy to local anaesthetic. It is important to explain the procedure and to obtain informed consent. A sterile technique is used and the first step is adequate disinfection of the skin or mucosa to prevent infection (Figure 3.1). Iodine is often used but a colourless and foam free antiseptic such as chlorhexidine is useful to maintain a clear vision of the lesion. If necessary, the hair should be removed. Figure 3.1 The area to be biopsied is cleaned with antiseptic. The use of an injectable local anaesthetic such as 1–2% lidocaine, is always required. Topical local anaesthetic cream may be used for small biopsies in the vestibule and is sometimes used to reduce the pain of injecting the local anaesthetic at other vulval sites. However, it is again vital that the pathologist knows the usual practice of the clinician, as pathological artefacts induced by EMLA® (prilocaine/lidocaine mixture) can lead to major diagnostic pitfalls. Infiltration (2–5 ml) is performed with subepidermal injection using a thin 30‐gauge needle (Figure 3.2). Figure 3.2 Local anaesthetic is infiltrated. The cold‐knife or Keye’s punch (Figure 3.3) are the most suitable tools for a correct vulval incisional biopsy. Shave biopsies are not adequate for diagnosis, particularly for inflammatory dermatoses. In general, punch biopsies
How to Take a Vulval Biopsy and the Importance of Clinico‐Pathological Correlation
Incisional biopsy
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