Margin Status in Shave Biopsies of Nonmelanoma Skin Cancers: Is It Worth Reporting?

Abstract

Context.-The practice of reporting margin status in biopsies is relatively unique to biopsies of the skin and highly variable among pathologists.Objective.-To address the accuracy of margin evaluation in shave biopsies of nonmelanoma skin cancers.Design.-We collected shave biopsies of squamous and basal cell carcinomas that appeared to have uninvolved margins on routine sign out. We obtained deeper levels on corresponding tissue blocks until blocks were exhausted and examined them for tumor at biopsy margins.Results.-Forty-seven consecutive cases were collected, including 20 squamous cell (43%) and 27 basal cell (57%) carcinomas. Eleven of 47 cases (23%) with negative margins at initial diagnosis demonstrated positive margins upon deeper-level examination. Margins of 8 of 27 basal cell carcinomas (30%) and 3 of 20 squamous cell carcinomas (15%) were erroneously classified as ''negative'' on routine examination.Conclusions.-No guidelines exist regarding the reporting of margins in nonmelanoma skin cancer biopsies, and reporting practices vary extensively among pathologists. We found that nearly one-quarter of positive margins in shave biopsies for cutaneous carcinomas are missed on standard histologic examination. Moreover, reporting of a positive margin may also be misleading if the clinician has definitively treated the skin cancer at the time of biopsy. For these reasons, and as routine exhaustion of all tissue blocks is impractical, the decision to include or exclude a comment regarding the margin status should be given conscious consideration, accounting for the clinical intent of the biopsy and any known information regarding postbiopsy treatment.

Updates on the Management of Non-Melanoma Skin Cancer (NMSC)

“…In the same context, a recent study brings up another critical point while questioning the value of reporting margin status in biopsies of NMSC. Based on their findings, 23% of cases with negative margins on initial biopsy demonstrated positive margins upon deeper-level examination [ 97 ] to further highlight the significance of proper interpretation of biopsy results when formulating a treatment plan.…”

Margin Reanalysis With 3-Dimensional Micrographic Surgery Technique of Conventional Excision Specimens With Negative Margin Readings

“…Their results did not reach statistical significance between the possibility of finding a false negative margin in BCC versus SCC. 6 The margin of a biopsy may often be narrower than the one used in a purportedly curative surgery, as indicated in our patients; therefore, our results are not comparable. This explains, in part, why their positive margin rate was much higher than ours.…”

Reliability of Biopsy Margin Status for Basal Cell Carcinoma: A Retrospective Study

“…This study similarly determined true margin status by assessing the margins at complete tissue block exhaustion. 4 Willardson et al 5 also demonstrated the poor predictive value of margin status based on the presence of residual BCC in subsequent excisions. They found that 34 (24%) of 143 cases with negative biopsy margins contained residual tumor in the corresponding excision.…”

“…Our findings support prior smaller studies investigating this topic. A prospective study by Schnebelen et al 4 examined 27 BCC biopsy specimens and found that 8 (30%) were erroneously classified as negative on routine examination. This study similarly determined true margin status by assessing the margins at complete tissue block exhaustion.…”