An incisional biopsy is indicated when the lesion measures larger than 1 cm in all dimensions.

• A. 0.5 cm in all dimensions
• B. 1 cm in all dimensions
• C. 1.5 cm in all dimensions
• D. 2 cm in all dimensions

Answer: (B)

The main idea is deciding when to sample only part of a lesion versus removing it entirely. An incisional biopsy is used when the lesion is of a size where a representative portion can be sampled without removing the whole thing, allowing the diagnosis to be established while preserving most of the lesion for potential future treatment. In practice, about 1 cm in all dimensions is the threshold where many clinicians opt for an incisional biopsy: the lesion is large enough that complete excision isn’t always necessary or ideal for diagnosis first, yet small enough that a single representative sample can still inform treatment planning.

If the lesion is smaller than this, removing it in one piece (an excisional biopsy) often provides both diagnosis and cure. If it’s larger than this, you might still perform an incisional biopsy to obtain a diagnosis before deciding on a more extensive surgical plan, but the simple rule used in this context is that a lesion about 1 cm in each dimension is the typical scenario where an incisional approach is indicated. The other sizes are either more appropriate for complete excision (too small to require sampling) or represent larger lesions where the choice depends on location and clinical judgment.