Growing Adoption of Immunohistochemistry by Mohs Micrographic Surgeons: A National Medicare Trend Analysis.

BACKGROUND:Immunohistochemical (IHC) staining can be used alongside Mohs micrographic surgery to aid in margin assessment of subtle tumors, yet existing estimates of IHC utilization have primarily relied on survey or older data that lacks stratification. OBJECTIVE:To characterize national IHC utilization trends by Mohs surgeons, stratifying by surgeon characteristics and modeling future adoption. METHODS:Longitudinal analysis of 2014 to 2021 Medicare Public Use Files. RESULTS:In 2021, 158 of 2,058 Mohs surgeons (7.7%) used IHC as compared with 4.0% in 2014 (average annual growth rate [AAGR] +3.6%). Adoption change was highest in the Northeast (AAGR +19.9%), whereas volume growth was greatest in the West (AAGR +25.2%). Multivariable regression revealed significantly greater utilization propensity among Mohs surgeons in academics (adjusted odds ratio [aOR] 3.36), American College of Mohs Surgery (ACMS) members (aOR 2.12), and Micrographic Dermatologic Surgery (MDS)-certified surgeons (aOR 1.66). CONCLUSION:Mohs surgeons are steadily incorporating IHC into practice across all regions, with volume growth driven by higher adoption rates. Greater utilization among ACMS members, recipients of MDS certification, and those in academics suggests value of formalized training in enhancing comfort. Additional educational opportunities at conferences may aid in recognition of value and help identify solutions to address integration challenges.