FLEX October 2023

B UCHANAN ET AL .

power settings of 1 W was 469.72 6 229.26 l m, 2 W 548.69 6 222.88 l m, and 3 W 335.03 6 169.67 l m. The overall average across all power settings was 451.15 6 207.27 l m (Figure 2B). DISCUSSION Acquisition of tumor-free surgical margins after laser excision of glottic squamous cell carcinoma, as with other malignancies, is of prime importance. A positive surgical margin is associated with increased local recurrence rates and shorter disease-specific survival, 12–15 usually necessi tating further excision to obtain a clear margin. Despite the advantages conferred by laser excision of early laryn geal cancer, as stated above, pathologists may be unable to comment confidently on the presence or absence of tumor cells or epithelial dysplasia at or near the margins because of the considerable artifact induced by laser treat ment. This artifactual keratinocyte atypia includes nuclear hyperchromasia and pleomorphism, which can be indistin guishable histologically from epithelial dysplasia. These cytologic changes were observed in all 30 cases examined in this study, and could be misinterpreted as epithelial dysplasia, thereby leading to under or overdiagnosis. His tologic assessment is best made at those areas of tissue lacking artifact. In areas of the tissue where the laser has

FIGURE 1. (A) Cordectomy specimen obtained with CO 2 laser, stained with hematoxylin-eosin, demonstrating extent of connec tive tissue denaturation (305.9 l m) (original magnification 3 264). (B) Cordectomy specimen obtained with CO 2 laser, stained with hematoxylin-eosin, demonstrating extent of epithe lial coagulative atypia (original magnification 3 305).

disturbance of normal architectural arrangements. These features mimic true cytologic atypia, which may be incor rectly interpreted as pleomorphism of the epithelial cells (Figure 1B). The mean distances of denaturation of the collagen and epithelium at different power settings are displayed in Figures 2A and 2B, respectively, and demonstrate a trend ( p > .05) that, as the power increases, the extent of dena turation decreases. The mean distance of collagen denatu ration of connective tissue for power settings of 1 W was 321.96 6 132.30 l m, 2 W 300.26 6 127.82 l m, and 3 W 297.40 6 123.02 l m. The overall average across all power settings was 310.50 6 150.30 l m (Figure 2A). The mean distance of epithelial denaturation of connective tissue for

FIGURE 2. (A) Mean depth of collagen denaturation according to laser power (error bars are SEM; p > .05). (B) Mean depth of epi thelial denaturation according to laser power (error bars are SEM; p > .05).

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HEAD & NECK—DOI 10.1002/HED APRIL 2016