PracticeUpdate Dermatology May 2019

EXPERT OPINION 19

Tissue-Sparing Properties of Mohs Micrographic Surgery for Infiltrative BCC By Ashish C. Bhatia MD, FAAD

Dr. Bhatia is an Assistant Professor of Clinical Dermatology at the Feinberg School of Medicine of Northwestern University in Chicago, and Medical Director for Dermatologic Research at the Department of Clinical Research at the DuPage Medical Group in Illinois.

I t is commonly accepted that Mohs micrographic surgery (MMS) provides the highest cure rate for cutaneous malignancies. In addition, smaller margins are taken com- pared with margins in standard excision, which results in sparing of healthy tissue surrounding the tumor. In this study, the authors examined the amount of tissue-sparing associated with MMS when used to treat primary basal cell carcinoma (BCC) with an infiltrative growth pattern on the face and scalp. 1 This particular subtype of BCC has a more aggressive course than nodular BCC, and complete removal is extremely important. The tissue-sparing was measured two dimensionally (X x Y) and did not account for depth. The MMS defect size was measured and compared with the anticipated defect size with a 5-mm margin associated with a standard excision. Of the 256 facial MMS BCCs in this prospective study, the majority were located on the nose. This is anatomically one of the more complex areas of the face, and it can greatly benefit from tissue-sparing since there is limited excess adjacent tissue for reconstruc- tion. Additionally, the surgeon must take into account the added complexity of distortion of the free margins of the alar rim as well as functional issues which can arise from recon- struction, such as nasal valving during inspiration. The authors found that, overall, the tissue-sparing fromMMS for facial infiltrative BCCs was 43% to 49% compared with standard excision. Also, in 8.6% of cases, the larger standard excision margins would have resulted in positive margins. Interestingly, the areas where MMS has the most tissue-sparing effect is the nose; that effect is lower for tumors on the cheek, forehead, and temples. This is the inverse of the areas where standard excision would lead to positive margins, which is much higher on the cheek, temples, and fore- head. These data support the utilization of MMS for primary infiltrative BCC on the face and scalp over standard excision, since MMS results in smaller defects and higher cure rates. Reference 1. Van Kester MS, Goeman JJ and Genders RE. Tissue-sparing properties of Mohs micrographic surgery for infiltrative basal cell carcinoma. J Am Acad Dermatol 2019 Jan 30;[EPub Ahead of Print]. This commentary is based upon the article Tissue-Sparing Properties of Mohs Micrographic Surgery for Infiltrative Basal Cell Carcinoma by van Kester MS et al. www.practiceupdate.com/c/79413

VOL. 3 • NO. 2 • 2019