San Antonio Military Medical Center, TX (Dr. Wohltmann); Uniformed Services University of the Health Sciences, Bethesda, MD (Dr. Servey) jessica.servey@usuhs.edu
The authors reported no potential conflict of interest relevant to this article.
The views expressed here are those of the authors and do not reflect the official views or policy of the Department of Defense or its components.
Skin biopsy is the definitive way to diagnose melanoma. Prior to biopsy, take photographs to document the exact location of the lesion and to ensure that the correct area is removed in wide excision (WE). A complete biopsy should include the full depth and breadth of the lesion to ensure there are clinically negative margins. This can be achieved with an elliptical excision (for larger lesions), punch excision (for small lesions), or saucerization (deep shave with 1- to 2-mm peripheral margins, used for intermediate-size lesions).18 Saucerization is distinctly different from a superficial shave biopsy, which is not recommended for lesions with features of melanoma.19
A decision to perform a biopsy on a part of the lesion (partial biopsy) depends on the size of the lesion and its anatomic location, and is best made in agreement with the patient. If the lesion cannot be removed in its entirety and a partial biopsy is necessary, take the sample from the most atypical appearing area and communicate this decision to the pathologist on the biopsy order. There is no evidence that performing a partial biopsy increases the risk of spreading melanoma.20,21
If you are untrained or uncomfortable performing the biopsy, contact a dermatologist immediately. In many communities, such referrals are subject to long delays, which further supports the advisability of family physicians doing their own biopsies after photographing the suspicious lesion. Many resources are available to help family physicians learn to do biopsies proficiently (www.mdedge.com/familymedicine/article/164358/oncology/biopsies-skin-cancer-detection-dispelling-myths).19
What to communicate to the pathologist. At a minimum, the biopsy request form should include patient age, sex, biopsy type (punch, excisional, or scoop shave), intention (complete or partial sample), exact site of the biopsy with laterality, and clinical details. These details should include the lesion size and clinical description, the suspected diagnosis, and clinical information, such as whether there is a history of bleeding or changing color, size, or symmetry. In standard biopsy specimens, the pathologist is only examining a portion of the lesion. Communicating clearly to the pathologist may lead to a request for deeper or additional sections or special stains.
Complete biopsy of a concerning pigmented lesion is the standard. If, however, a partial biopsy is necessary, sample the most atypical area.
If the biopsy results do not match the clinical impression, a phone call to the pathologist is warranted. In addition, evaluation by a dermatopathologist may be merited as pathologic diagnosis of melanoma can be quite challenging. Newer molecular tests, such as fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH), can assist in the histologic evaluation of complex pigmented lesions.
