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

Processing and evaluation of tissue. (A) Specimen after resection (Patient No. 44: oral squamous cell carcinoma; T2N0M0). Circle and black line indicate color measuring point for USLs and cut mark of boundary line between SLs and USLs, respectively. (B) Histopathological diagnosis corresponding to sections of specimen. Arrows indicate surgical margin area defined as the tissue surrounding the adjacent marginal area. Yellow line, mild epithelial dysplasia; green line, moderate epithelial dysplasia; pink line, severe epithelial dysplasia; red cross, cancerous lesions; black line, cut mark of boundary line between SLs and USLs; white circle, color measuring point for USLs. (C) Arrow indicates shallow incision in the specimen showing macroscopic boundary line between SLs and USLs (H-E staining ×40). (D) Schema for measurement of deviation. The deviation was defined as the distance between the macroscopic and histopathological boundary lines. The histopathological border in the specimen is indicated by the zero point.

Staining results and histopathological examinations. Case 1 (A–D): (A) Condition clinically diagnosed as OSCC of the tongue (T2N0M0). (B) Iodine staining result. Measuring point for the color of the USLs is indicated by the asterisk. (C) SLs (PAS staining ×100). (D) Mild epithelial dysplasia (PAS staining ×100). The epithelial layer has hardly any stained cells and there are a few atypical cells in the basal layer. Case 2 (E–H): (E) Condition was diagnosed as OSCC of the tongue (T3N0M0). (F) Iodine staining result. Measuring point for the color of the USLs is indicated by the circle. (G) SLs (PAS staining ×100). (H) Moderate epithelial dysplasia (PAS staining ×100). Loss of the polarity of basal cells and irregular epithermal stratification were remarkable compared with those observed in mild epithelial dysplasia. Case 3 (I–L): (I) Condition was diagnosed as OSCC of the tongue (T2N0M0). (J) Iodine staining result. Measuring point for the color of the USLs is indicated by the circle. (K) SLs (PAS staining ×200). (L) Severe epithelial dysplasia (PAS staining ×200). Nuclear hyperchromatism and increased nuclear–cytoplasmic ratio in cells were found. Each white square indicates SLs (control) adjacent to USLs.

Color charts of results of tongue stained with 3% Lugol's solution. (a) normal stained area, (b) mild epithelial dysplasia, (c) moderate to severe epithelial dysplasia.

Rates (%) of PAS-stained cells (n=34). (A) Shows USLs, SLs and surgical margin area (SMA). (B) Shows epithelial hyperplasia (HYP, n=5), mild epithelial dysplasia (MLD, n=11), moderate to severe epithelial dysplasia (MOD/SED, n=18). The results are presented as means±SD (bars). Tukey's multiple comparison test (* P<0.05) was used for statistical analysis. In (A) there were significant differences between USLs and SLs (**P<0.001), USLs and SMA (**P<0.001). In (B) there was a significant difference between HYP and MOD/SED (*P=0.035). No significant difference was evident between HYP and MLD (P=0.119).