New Imaging Approach Shows High Agreement in Mohs Margin Assessment: Study
Key Takeaways
Ex vivo fluorescence confocal microscopy (EVFCM) achieved 96.4% overall diagnostic accuracy for intraoperative margin assessment in nonmelanoma skin cancer.
Dermatologist and pathologist readers demonstrated 98.6% observed agreement on margin assessments across a prospective Mohs surgery study.
Two discrepancies with conventional histopathology were reported, including one false-negative margin assessment. Additional research is needed to establish workflow benefits, authors concluded.
A recent Modern Pathology study reported found that ex vivo fluorescence confocal microscopy (EVFCM) achieved high overall diagnostic accuracy in assessing surgical margins during Mohs surgery for nonmelanoma skin cancer (NMSC).
EVFCM Shows Strong Agreement With Histopathology in Mohs Surgery
Researchers evaluated 42 tumors from 39 patients undergoing Mohs surgery. Investigators examined 261 peripheral and deep margins using a new-generation EVFCM system that produces hematoxylin-eosin-like digital images.
Specimens underwent orthogonal sectioning and staining before independent, blinded assessment by an EVFCM-trained dermatologist and pathologist. Concordant negative findings were classified as tumor-free, while positive, discordant, or equivocal results prompted additional excision and evaluation.
Interobserver agreement was high for margin assessment (κ = 0.863; P < 0.001), with 98.6% observed agreement. Agreement on tumor histotype was similarly strong (κ = 0.882; P < 0.001), with 97.6% observed agreement. EVFCM demonstrated 96.4% overall diagnostic accuracy vs conventional histopathology. The combined assessment yielded an area under the curve of 0.875 (95% CI, 0.730 to 1.000).
Source
Spadafora M, et al. Modern Pathology. 2026. Doi:10.1016/j.modpat.2026.101095