ANGIOGENIC SQUAMOUS DYSPLASIA -LIKE PHENOMENON IN ORAL EPITHELIAL PRECURSOR LESIONS

Statement of the problem: Dysplasia, the morphologi cal yardstick of epithelial precursor lesions, is the col lective term for a variety of architectural and cytologi cal changes within the altered oral epithelium. Angio genic squamous dysplasia (ASD), a distinct morpho logical characteristic in pre-invasive bronchial lesions, describes the presence of capillary tufts that are close ly juxtaposed to and projecting into the dysplastic bronchial epithelium. Objective: To determine whether ASD-like phenome non occurs in oral epithelial precursor lesions, and to speculate on its relevance. Methods: Twenty cases each of mild, moderate and se vere oral dysplasia (inclusive of carcinoma-in-situ), and 10 normal oral mucosa (normal controls) were se rial sectioned for H and E staining, and for microves sel density (MVD) scoring with CD31, CD34 and CD105. Microcapillary pattern images were digitally captured for 3-D reconstruction. Results: Oral ASD foci consisting of CD31- and CD34-positive capillary loops abutting onto the overly ing dysplastic oral epithelium (and causing it to assume an irregular or papillary surface configuration) were identified in moderate (3/20; 15%) and severe dysplasia (13/20; 65%), but not in normal oral mucosa and mild dysplasia. MVD score demonstrated increasing vascu larity as epithelium progressed from normal to severe dysplasia (p<0.05). CD105 demonstrated increase neo vascularization in all dysplasia grades (p<0.05). Conclusions: These preliminary findings taken together suggest that: 1. ASD-like phenomenon may be an im portant intermediary biomarker in oral precursor le sions; and 2. architectural alterations of the entire dis turbed mucosa may be a more useful pre-malignancy index.