| Abstract: | Changes in basement membrane (BM) structure were studied in functioning and hyperplastic endometrium, in adenocarcinomas with various degrees of differentiation and in progesterone-treated adenocarcinomas using electron microscopy and immunohistochemical staining with antibodies against human type IV collagen and laminin. These BM components were distinctly visualized as narrow, continuous bands beneath the epithelium and around the endometrial glands in functioning, atrophic and hyperplastic endometrium. In well-differentiated endometrial carcinomas there was mostly a continuous BM, though occasional disruptions were seen. The undifferentiated tumors, on the other hand, were characterized by the absence of a continuous BM structure, although irregular patches of BM material were found within the neoplasm. Hormonal treatment caused the reappearance of the BM structures. According to these results, the visualization of the BMs in the endometrium not only increases our understanding of tumor behavior, but can also be used as an aid for the classification and treatment of endometrial neoplasms. |
