Minute and small early gastric carcinoma with special reference to eosinophil infiltration.

The authors examined 25 minute early gastric cancers (EGC) and 13 small EGC in order to investigate the incidence and possible causes for the infiltration of eosinophils. The degree of eosinophil infiltration was higher in tumour stroma than in adjacent normal-appearing mucosa; this correlation was statistically significant (P < 0.001). Tumour-associated tissue eosinophilia (TATE) was not correlated with size, histological type, necrosis of the tumour nor gastritis activity in adjacent non-tumoral mucosa. Electron microscopy, performed in 4 cases of small EGC, showed tumour stromal eosinophils with morphological evidence of activation similar to those described for tissue eosinophils in various disorders. Some tumour cells in intimate contact with activated eosinophils exhibited focal cytopathic changes. TATE represents local inflammation probably leading to tumour cell damage. The immunological role of the eosinophils against tumour cells in vivo deserves further investigation.