Colorimetric analysis of unstained lesions surrounding oral squamous cell carcinomas and oral potentially malignant disorders using iodine

To determine whether the measurement of staining with 3% Lugol's solution provided efficient criteria for determining the area of resection for oral carcinomas and oral potentially malignant disorders, the authors analyzed the color of unstained lesions (USLs) in relation to histopathological findings. After vital iodine staining, USLs were seen in 48 of 54 patients (88.9%). A significant difference was seen in the value of lightness between stained lesions (SLs) and USLs for patients with moderate and severe epithelial dysplasia (P < 0.001). The deviation between the macroscopically observable and the histopathological boundaries was −0.65 ± 1.26 mm (range: −4.36 to 1.52). Color charts prepared on the basis of values for lightness and hue reproduced the macroscopic color differences in USLs, suggesting that it may become possible to diagnose USLs histologically on the basis of the measured color values and use of color charts to help determine the resection area in surgery.