Figure 1

Immunohistochemical profiles for milk fat globule—epidermal growth factor—factor VIII (MFG-E8) in normal epithelia and squamous cell carcinoma (SCC) of the oral mucosa. Normal epithelial parts (a, b) and SCC (c–h) of the tongue; (a–h) immunoperoxidase stain for MFG-E8, hematoxylin counter stain. (a, b, d–f), × 200; (c), × 40; (g), × 400, (h), × 600. In normal mucosa, there was no positive staining for MFG-E8 in the covering squamous epithelium or in the lamina propriae (a). In the submucosal layer, MFG-E8 was localized in ductal and acinar epithelial cells of the mucous gland or in endothelial cells of muscular blood vessels (b). In SCC, carcinoma cells showed varying staining patterns from strong (c, d), to weak (e), to nothing (f). Intensive staining was observed in SCC cells forming smaller foci (c) and in singularly isolated cells (g) in the invasive front towards muscle tissues. Within invading SCC foci, MFG-E8 was diffusely positive in the cytoplasm of SCC cells (h). In addition, MFG-E8 was concentrated in apoptotic SCC cells, some of which seemed to be engulfed by neighboring living SCC cells (h, arrows).