Surgical margins required for basal cell carcinomas treated with Mohs micrographic surgery according to tumor features

Abstract

1. Trump DJ. Proclamation on declaring a national emergency concerning the novel coronavirus disease (COVID-19) outbreak. Available at: https://www.whitehouse.gov/presidential-actions/ proclamation-declaring-national-emergency-concerning-novelcoronavirus-disease-covid-19-outbreak/. 2020. Accessed October 12, 2020. 2. CARES Act, S.3548, 116th Congress. Available at: https://www. congress.gov/bill/116th-congress/senate-bill/3548/text. 2020. Accessed October 11, 2020. 3. Gisondi P, Piaserico S, Conti A. Dermatologists and SARS-CoV-2: the impact of the pandemic on daily practice.

Clinicopathological factors influencing the number of stages of Mohs surgery for basal cell carcinoma

“…Regarding high-risk location, there is a statistically significant difference in a number of stages between tumors located in the periocular region and tumors of the ear, nose, or perioral area, with periocular BCCs requiring more stages of surgery. Although location on high-risk areas was shown to be associated with a higher number of stages in previous studies, 4 , 5 , 7 the specification and comparison between various high-risk areas are more rarely mentioned in the literature.…”

“…This was not according to other studies, in which preoperative size was a significant predictor of larger margins and number of stages, especially when tumors had > 20 mm. 7 , 10 , 11 …”

“… 6 In a very recent study, Cerci et al concluded that not just micronodular, infiltrative, and morphea form histological subtypes were associated with larger margins but also superficial ones (due to greater subclinical extension); whereas clinically well-defined and small tumors needed smaller margins, with tumors < 6 mm having a clearance rate of 96% with 3-mm margins; preoperative tumor size was a significant predictor of larger margins and number of MMS stages. 7 Another recent retrospective study evaluated the characteristics of Basal Cell Carcinoma with Large Subclinical Extension (BCC-LSE), a tumor whose extensive spread becomes apparent during the Mohs surgery histopathology review. Of a total of 2044 cases that met the criteria of BCC-LSE (defined as a lesion requiring at least three Mohs stages and a final surgical margin of ≥10 mm), male sex (p = 0.05), Fitzpatrick skin type I (p = 0.002), history of prior BCC (p = 0.003) and subtypes of basosquamous, metatypical, micronodular, infiltrative, morpheaform and sclerosing (p = 0.005) remained significant BCC-LSE predictors.…”

“…Although MMS has been shown to be tissue-sparing, few studies correlated margins required for clearance to tumor characteristics. 7 Recently, Ariza et al demonstrated that a 4 mm resection margin was enough to completely eradicate the tumor in 99% of cases of primary small (≤6 mm) facial BCCs, even with aggressive histological patterns (micronodular, infiltrative, or morpheaform). Smaller margins of 2 and 3 mm achieved complete excision of the lesion in 73.9% and 94.4% of cases, respectively.…”

Mohs micrographic surgery: a review of indications, technique, outcomes, and considerations

“… 91 , 92 A recent study that evaluated margins (in mm) required for primary BCC clearance showed that the most significant factors related to larger margins were superficial, micronodular, infiltrative, and morpheaform subtypes; whereas clinically well-defined tumors were associated with smaller margins. 93 …”