MAST-CELL INTERACTION WITH TUMOR-CELLS IN SMALL EARLY GASTRIC-CANCER - ULTRASTRUCTURAL OBSERVATIONS

The authors studied the mast cells by light and electron microscopy in four small intramucosal early gastric cancers (EGC). Mast cells were found in the tumor stroma and among neoplastic cells of adenocarcinoma glands. Stromal and adenocarcinoma-infiltrating mast cells were ultra structurally identified as T mast cells, and exhibited anaphylactic or piecemeal degranulation. Tumor cells in intimate contact with mast ce lls showed no cytopathic changes. These data do not support a mast cel l-mediated cancer lysis, such as that reported in some systems in vitr o. The interepithelial localization of T mast cell in adenocarcinoma g lands is similar to that observed in some disease states, including in terstitial cystitis, fibrotic lung disorders, and mucosal allergic rea ction. The findings suggest that T mast cells may be involved in the p athophysiology of the host reaction to small intramucosal EGC.