Biopsy Techniques for Suspected Melanoma

Primary Decision Algorithm for Suspected Melanoma

The American Academy of Dermatology recommends performing a narrow excisional biopsy with 1-3 mm margins as the preferred technique for suspected melanoma, while superficial shave biopsies are generally discouraged except for macular lesions suggestive of melanoma in situ, lentigo maligna type 1, 2, 3
For raised or nodular lesions concerning for melanoma, complete excision with 1-3 mm margins extending to sufficient depth to prevent transection at the base is the gold standard, which can be accomplished by fusiform/elliptical excision, punch excision, or deep shave/saucerization 1, 2, 3, 4
Superficial shave biopsies may underestimate Breslow thickness and clinical stage, potentially leading to incorrect staging and treatment planning, with a critical rationale that they should not be performed for suspected invasive melanoma 2, 3, 4, 5, 6

For macular lesions suggestive of melanoma in situ, lentigo maligna type, a broad shave biopsy extending into the deep papillary or superficial reticular dermis provides more thorough histologic assessment of potential focal microinvasion than multiple punch biopsies 2, 3, 5, 7, 6
Suspicious nail lesions require nail matrix sampling, with the nail plate sufficiently removed to expose the underlying lesion, and biopsy clinically obvious tumor if present 2, 3, 4, 5

Diagnostic shave biopsies should not be performed as they lead to incorrect diagnosis due to sampling error and make accurate pathological staging impossible, which is the most common error that compromises patient outcomes 8
Partial removal of a melanocytic nevus may result in pseudomelanoma, causing needless anxiety, and for atypical nevi, shave biopsy is acceptable as these are frequently diagnosed using this technique 8, 9

For excisional biopsy, include 1-3 mm peripheral margin around the concerning lesion, extend to sufficient depth to ensure the lesion is not histologically transected at the deep margin, include a cuff of fat, and orient the excision axis to facilitate possible subsequent wide local excision 1, 2, 3, 8
For deep shave/saucerization, must extend into deep papillary or superficial reticular dermis, use topical hemostatic agents preferred over electrocautery, and absorbable gelatin coagulants can be added 2, 3, 5, 7, 6

Pre-biopsy photographs are essential, including regional photograph with anatomic landmarks to aid clinical/pathologic correlation and prevent wrong-site surgery 1
Provide pertinent clinical information to pathologist including level of suspicion for melanoma, clinical description, and lesion history 7, 6