Stromal reaction to neoplasia: colonic carcinomas

The stroma and stromal reaction in the normal colon and in 14 different colonic tumors were studied by electron microscopy. Elastosis is a significant part of the stromal reaction to colonic adenocarcinomas and rectal squamous cell carcinomas. Two carcinoid tumors elicited no significant elastosis. In some of the adenocarcinomas, small muscular arteries close to neoplastic tissue developed massive elastosis of the media. This may indicate that the elastosis is due to stimulation of nonneoplastic stromal cells by some unknown neoplastic factor or factors.