Abstract

Primary antibody to a ubiquitous component of basement membrane, type IV collagen was applied to farmalin-fixed and paraffin embedded tissue sections of a variety of tumorous conditions; benign tumor, dysplastic lesions, intraepithelial neoplasms and invasive carcinomas to determine the status of basement membrane alteration by immunohistochemical and u1trastructural examinations. Included lesions of this study were breast(fibroadenoma, intraductal carcinoma, and infiltrating duct carcinoma), colon(adenocarcinoma, well to poorly differentiated), stomach(adenocarcinoma, well to poorly differentiated), uterine cervix (dysplasia, microinvasive and invasive squamous cell carcinoma) and metastatic adenocarcinoma in the lymph nodes(of stomach and colon). By immunoperoxidase techniques, benign tumors and dysplasias showed intact basement membranes with linear staining pattern for the type IV collagen. In contrast, the majority of the invasive carcinomas lacked immunoreactivity for the basement membrane components. In the case of microinvasive carcinomas, there were thinning, fragmentation and disruption of the basement membrane in the foci of microinvasion, but not in elsewhere. Ultrastructural observations showed intact basement membranes in the benign tumors and dysplastic lesions, while thinned and/or fragmented basement membranes in the intraepithelial malignancy and microinvasive carcinomas. There were no differences of immunostaining patterns of the basement membrane between the well and the pooly differentiated neoplasms. Also there were no immunohistochemical differences between the primary and the metastatic adenocarcinomas. In conclusion, immunohistochemical staining for type IV collagen and ultrastructural observations for basement membrane will be useful to determine of tumor invasiveness and degree of differentiation.

• Keywords: Basement membrane, Type IV collagen, Ultrastructure, Immunohistochemistry, Benign, Malignant