Venous permeation of colorectal carcinoma.

Two hundred and fifty-six tumors of carcinoma of the colon and rectum which had been surgically removed five or more years previously, and preserved in paraffin blocks, were examined for venous invasion using both routine hematoxylin and eosin (H-E) and by special stain for elastic fibers. In all these samples, 156 (61%) showed histological evidence of venous invasion and such was most frequently seen in the submucosa, followed by the subserosa or the perirectal fat. Since most of the involved veins showed marked destruction of the wall structure and were associated with total obstruction of the lumen, identification was difficult using the routine H-E strain. The frequency of venous invasion varied with the gross type of the tumor, the depth of penetration and the degree of differentiation, although there was no relation to size or to the site of the tumor. The incidence increased in cases of evident lymphatic permeation or lymph node involvement. The number of patients with venous invasion and a 5-year survival rate was significantly decreased, particularly in the Dukes' C cases. Thus, the determination of the extent of venous invasion using the elastic tissue stain is of definite prognostic value.