A Retrospective Comparison Between Preoperative and Postoperative Breslow Depth in Primary Cutaneous Melanoma: How Preoperative Shave Biopsies Affect Surgical Management
May 2014 | Volume 13 | Issue 5 | Original Article | 531 | Copyright © May 2014
Michael Saco MDa,b and Jack Thigpen MD FACSb
aDepartment of Dermatology & Cutaneous Surgery, University of South Florida, Tampa, FL
bWatson Clinic Center for Cancer Care & Research in Lakeland, FL, an affiliate of the H. Lee Moffitt Cancer Center & Research Institute
BACKGROUND: Accurate histopathologic staging of preoperative biopsy specimens is critical for determining optimal surgical management for patients with primary cutaneous melanoma. The American Academy of Dermatology (AAD) and National Comprehensive Cancer Network (NCCN) currently list narrow excisional biopsy (fusiform excision) as the preferred technique for biopsying lesions suspicious for melanoma. However, preoperative shave biopsies are routinely performed on lesions concerning for melanoma in many medical centers out of convenience.
OBJECTIVE: The current retrospective chart review was performed to determine whether preoperative shave biopsies are acceptable for evaluating lesions suspicious for melanoma and whether shave biopsies lead to underestimation of Breslow depth great enough to require additional surgeries.
METHODS: A consecutive sample of 242 primary cutaneous melanoma cases surgically excised between January 1, 2004 and December 31, 2010 in a private practice setting was analyzed for this study.
RESULTS: Breslow depth underestimation occurred in 8 of 226 shave biopsy cases (3.5%). Differences in preoperative and postoperative Breslow depths in shave biopsy cases were not statistically significant (P=0.48). Underestimation of Breslow depth, melanoma transection, positive deep biopsy margins, and tumor upstaging did not lead to statistically significant changes in surgical management.
CONCLUSIONS: Based on the results from the current study and available literature, the authors posit that preoperative deep excisional shave biopsies performed by dermatologists are accurate for determining Breslow depth and for planning surgical management of melanomas. J Drugs Dermatol.
Histopathologic examination of preoperative biopsy specimens remains paramount in terms of diagnosing melanoma. Rates of diagnosing melanoma accurately from a purely clinical basis leave much to be desired, with estimated
rates as low as 42% for primary care physicians and 80% for dermatologists.1 Information obtained from preoperative biopsies plays a vital role in planning the surgical approach to melanoma, such as determining margins for surgical excision and whether sentinel lymph node biopsy (SLNB) is indicated.2
According to the 2009 American Joint Committee on Cancer (AJCC) staging system, the three most important parameters for melanoma staging are Breslow depth, mitotic rate, and ulceration.3,4 Breslow depth has great prognostic significance for melanomas of all stages.4 Accordingly, the National Comprehensive
Cancer Network (NCCN) has based its guidelines regarding appropriateness of performing SLNB on Breslow depth. The NCCN does not recommend SLNB for patients with melanomas ≤ 0.75 mm. For melanomas 0.76-1.0 mm, SLNB should be discussed with the patient and considered by the physician as an option.2,3,5,6 Any patients with melanomas > 1 mm should receive a SLNB, as it is crucial in both melanoma staging and prediction of prognosis.2,5,7,8
The American Academy of Dermatology (AAD) and NCCN currently
recommend narrow excisional biopsy as the preferred method for preoperative biopsy of lesions suspicious for melanoma
since incisional biopsies and shave biopsies may lead to sampling error in the deep or lateral margins.2,4,9-11 Excisional biopsy may be inappropriate for very large lesions or for lesions
located in certain anatomic sites, such as the palms, soles of feet, face, ears, distal sites on fingers or toes, or subungual lesions. In these cases, a full thickness incisional or punch biopsy
of the section of the lesion that appears clinically thickest is acceptable.2,4 Shave biopsies are only considered acceptable when clinical suspicion for melanoma is low, based on the principle that shave biopsies may transect the melanoma and consequently compromise pathologic diagnosis and staging,