Objective: To study the immunohistochemical alteration of basement membrane (BM) type IV collagen and laminin in oral verrucous carcinoma and its BM ultrastructural variations.
Methods: 16 cases of oral verrucous carcinoma (OVC), 10 cases of oral squamous cell carcinoma (OSCC) and 9 cases of oral mild to severe epithelial dysplasia (OMSD) were studied by using a immunohistochemical S-P method, and the results were analyzed by quantitative method. 3 cases of OVC were observed by TEM.
Results: The BM in OVC was thicker than in OSCC and OMSD. TEM found the basal lamina in some areas showed a marked reduplication. The BM in OVC was generally intact (13/16), whereas in OSCC it was mostly discontinuous (9/10), especially around the neoplasm front or the small cord consisted of a few cells, and mostly continuous in OMSD (6/9). There was a stromal inflammatory infiltration around tumor nests for all the oral lesions, but it was much heavier in OVC than that in OSCC and OMSD (P < 0.05). There was a positive correlation between intraepithelial lymphocytic infiltration and the BM continuity for OVC(P < 0.01).
Conclusions: The more continuous BM and the heavier inflammatory infiltration in the connective tissue of OVC may be related to its biological behavior.