Skin biopsy techniques should be selected based on the type, size, and suspected diagnosis of the skin lesion to ensure adequate tissue sampling for accurate histopathological evaluation.
For small, superficial lesions such as suspected basal cell carcinomas or squamous cell carcinomas, a punch biopsy is generally recommended. This technique allows full-thickness sampling of the epidermis and dermis and is suitable for inflammatory or neoplastic lesions where depth assessment is important NICE NG14.
For larger or raised lesions, including suspected melanomas, an excisional biopsy with narrow margins is preferred to remove the entire lesion for complete histological assessment and accurate staging NICE NG14. This approach aligns with NICE melanoma guidelines emphasizing complete excision for suspicious pigmented lesions NICE NG14.
Incisional biopsies, where only a portion of a large lesion is sampled, may be used when excision is not feasible due to lesion size or location, particularly in cases of suspected lymphoma or other infiltrative dermatoses NICE NG14.
Shave biopsies are generally reserved for superficial lesions confined to the epidermis, such as seborrheic keratoses or superficial basal cell carcinomas, but are less preferred for pigmented lesions due to the risk of incomplete sampling and diagnostic uncertainty Craft et al. 2023.
Recent veterinary pathology literature highlights the importance of selecting biopsy technique based on lesion characteristics and suggests that punch biopsies provide a good balance of diagnostic yield and minimal invasiveness for many lesion types, while excisional biopsies remain the gold standard for suspected melanomas and other malignancies requiring margin assessment Craft et al. 2023.
In summary, the recommended approach is:
- Punch biopsy for small, non-melanoma lesions and inflammatory dermatoses NICE NG14, Craft et al. 2023.
- Excisional biopsy for suspected melanomas and larger lesions where complete removal is possible and necessary NICE NG14, Craft et al. 2023.
- Incisional biopsy for large or infiltrative lesions where excision is impractical NICE NG14.
- Shave biopsy for superficial epidermal lesions but with caution in pigmented lesions Craft et al. 2023.