[Vascular proliferation in the stroma of gastric cancer and its significance]

To elucidate vascular characteristics in the stroma of gastric cancer, the morphological and immunohistochemical changes of vascular components were examined in 27 gastric cancers and 7 noncancer gastric tissues including 2 peptic ulcers. In differentiated adenocarcinoma, a large number of blood vessels were observed in vicinity of the cancer glands and type IV collagen (C-IV) was localized around the blood vessels and cancer glands, and ultrastructurally, cytoplasmic organelle and weibel-Palade bodies were encountered in the endothelium. In poorly differentiated adenocarcinoma, a small number of blood vessels were distributed sporadically in the stroma and there were vascular endothelia in which von Willebrand factor (VWF) was localized, and there were much more endothelia in which VWF was not localized compared with differentiated adenocarcinoma. C-IV was localized only around the blood vessels and OKM5 was localized in the endothelia which were distributed in the center of cancer nest in poorly differentiated adenocarcinoma. Ultrastructurally, there were not so many Weibel-Palade bodies in the endothelia without complete basement membrane. The morphological and functional changes of blood vessels were correlated with cancer differentiation and metastasis. These changes may provide biological feature of cancer and may be induced by cancer cells, vascular endothelia and mesenchymal cells.