Mohs micrographic surgery histopathology concordance in fellowship-trained surgeons

To the Editor: We read with interest the excellent article by Mariwalla et al in the January 2009 issue of the Journal regarding the histopathology concordance between fellowship-trained Mohs micrographic surgeons and dermatopathologists in frozen section interpretation. The authors did mention that all of the participating Mohs surgeons were fellowship-trained and that a ‘‘well trained [Mohs micrographic surgeon] is capable of accurately interpreting tumors histologically in the therapeutic setting.’’ However, we believe that this deserves more emphasis. Accurate histologic examination of surgical margins is the foundation of Mohs micrographic surgery. This is best achieved by the experience of a 11 year structured fellowship. Extended time with both direct and indirect mentoring is essential in developing expertise in not only Mohs histopathology but also in wound care, anatomy, and reconstruction. Casey et al recently reported the standardization of fellowship-trained Mohs surgeons in a study of 50 Mohs surgery fellowship directors. Murphy et al examined the fellowship training process with respect to critical errors in Mohs histopathology. These studies reinforce the fact that experience coupled with immediate feedback is the optimal means to achieve Mohs histopathology excellence. Murphy et al showed that ‘‘proficiency in the interpretation of Mohs histopathology cannot be achieved in a matter of days, weeks, or months. Nor can it be achieved by looking at a few cases, tens of cases, or even a few hundred cases.’’ Mentored correction of errors in Mohs histopathology is essential to training. Technical and interpretive errors are the most important factors that affect the recurrence rate following Mohs micrographic surgery. This is directly related to thequality ofMohshistopathology,whichof course relates back to the quality of the Mohs surgeon.