POSSIBILITY OF DEFENSE AGAINST COLORECTAL TUMOR BY FOAMY CELLS

To investigate the difference between colorectal adenocarcinomas with white spots (foamy cells) and those without white spots, clinically an d histopathologically, we examined 112 cases of colorectal adenocarcin omas in this study. Thirty-two cases were diagnosed as submucosal inva sive adenocarcinoma and 80 as advanced adenocarcinoma. They were class ified into two groups: with white spots and without white spots. Submu cosal tumors and squamous epithelial-origin tumors were excluded. In e ach case we looked for evidence of lymph node and liver metastases. Im munoreactive staining for macrophages, foamy cells, T cells, and B cel ls was also performed. We found a significant difference in the incide nce of lymph node metastasis between the two groups with advanced carc inoma. White spots (foamy cells) were present at some distance from ca rcinoma cells. We conclude that foamy cells might have a beneficial ro le. From a histopathological viewpoint they can be considered a possib le physical defense wall, an index df immune response activation. Clin ically, it is important not to overlook any lesion.