Fig. 1

Intraoral and histological findings of dorsal tongue SCC. Intraoral findings of cases 1 (a), 2 (c), 3 (e), and 4 (g). Representative histological findings for cases 1 (b), 2 (d), 3 (f), and 4 (h). Black boxes show higher magnifications of b, d, f, h. The tumors exhibited irregular epithelial stratification and keratin pearl formation within the ridges. The tumors also exhibited nests or islands and infiltrated connective tissues. SCC, squamous cell carcinoma. Scale bars: 500 μm in Fig. b; 1000 μm in Figs. d, f and h; 200 μm in black boxes