Abstract
Dysplastic grade of the leukoplakia on the border of the tongue, particularly of the basal cells and the lamina propria, was assessed by immunohistochemistry.
The subjects were 50 patients with clinical leukoplakia, including 12 patients without dysplasia, 17 with mild dysplasia, 14 with moderate dysplasia, four with severe dysplasia and three with initial invasive squamous cell carcinoma (IISCC), and 10 patients each with so-called fibroma and deep invasive squamous cell carcinoma (DISCC) on the border of the tongue. The scoring system of dysplasia, grade of infiltrating lymphocytes, and loss of basement membrane as histological factors, as well as expression of ki-67, p53, glutathione S-transferase π (GST-π) UCHL-1, L-26, HLA-DR, and type IV collagen as immunohistochemical ones were examined.
The score of dysplasia corresponded well to the conventional dysplastic grade except for that of IISCC. Factors related with dysplastic grade were disarray of ki-67-expressing cells as the epithelial parameter, high degree of lymphocytic infiltration, predominantly T cells, and loss of type IV collagen in the lamina propria as the host-reactivity one. The number of HLA-DR-expressing cells was significantly decreased in leukoplakia and DISCC, although no correlation was found with some displastic grade.
These results suggest that dysplastic changes and subsequent malignant transformation may be caused by abnormal characteristics of both basal cells and the local immunodefense system.
