Biopsy techniques. Diagnosis of melanoma.

The biopsy of a suspicious pigmented lesion is critical to establishing a correct and complete diagnosis. It allows the dermatopathologist accurately to diagnose melanoma and to gauge maximum depth of invasion (and other histologic criterion). This, in turn, influences the extent of further necessary surgery or other adjuvant therapy. Furthermore, choosing the appropriate biopsy technique provides adequate cosmetic results, bearing in mind that the excisional technique is ideal because it removes the suspicious lesion en toto. Excisional biopsies should extend to the subcutaneous fat by means of a punch biopsy, a fusiform ellipse, or a saucerization. Incisional biopsies can be performed in certain circumstances, but should be done so with caution because sampling error may lead to missed diagnosis or inaccurate histologic criterion, such as depth.