Which is a contraindication for shave biopsy?

• A. Molluscum contagiosum
• B. Seborrheic keratoses
• C. Benign superficial lesions
• D. Hyperpigmented moles greater than 1 cm

Answer: (D)

Shave biopsy is best for superficial lesions where the goal is to sample or remove the top layers without needing deep tissue. The danger with a hyperpigmented mole larger than 1 cm is that it could be melanoma; shaving the lesion risks removing only the surface and leaving the deeper portions unassessed. Depth of invasion (Breslow thickness) is crucial for melanoma staging and treatment decisions, and you can’t accurately determine that from a partial, shallow shave. Therefore, a larger pigmented lesion suspicious for melanoma is a contraindication for shave biopsy because you need a full-thickness excisional biopsy with margins to evaluate invasion and provide proper staging.

Molluscum contagiosum, seborrheic keratoses, and benign superficial lesions are not contraindicated for shave biopsy because they are typically benign or easily diagnosed from superficial tissue, and removing the top layer often suffices for diagnosis or treatment without compromising critical depth information.