Vascular invasion of colorectal carcinoma readily visible with certain stains

We made use of hematoxylin and eosin (H&E) stain, Verhoeff van-Gieson stain for elastic tissue (EVG), and factor VIII-related antigen (FVIII-RA) to stain tissues excised from 94 patients with colorectal carcinoma. Of these 94, 49 died of disease within two years (Group I), and 45 survived for five years or longer (Group II) after surgery. In the tissues from both groups, the use of EVG stain revealed a higher incidence of vascular invasion than was seen with H&E stain. In Group I, the rates were 28.6 percent and 61.2 percent with H&E and EVG, respectively, and those in Group II were 4.4 percent and 31.1 percent, respectively. Conversely, the FVIII-RA stain showed a decrease in the incidence of vascular invasion in both groups. In Group I, when vascular invasion was examined in EVG-stained tissues, the incidence was 81.3 percent in cases of hematogenous metastases and 23.5 percent in those without hematogenous metastases (P less than 0.01). These differences were not evident with H&E. When observing the site of vascular invasion in tissues of the colorectal wall stained with EVG, intramural and extramural types of vascular invasion were seen in 20 percent and 80 percent of cases in Group I and in 93 percent and 7 percent of those in Group II, respectively. Thus, not only the frequency, but also the site, of vascular invasion into the colorectal wall evidenced with EVG stain provides a more precise prediction of the recurrence of hematogenous metastases.