Stereomicroscopic Investigation of the anal canal epithelium

Macroscopic specimens on the anal canal from 22 patients with colorectal carcinoma and 5 patients with anal canal carcinoma were investigated by stereomicroscopy after whole-mount staining with alcian blue. The specimens were thereafter cut up systematically and prepared for conventional light microscopy to correlate stereomicroscopic and histologic findings. The results show that different surface relief and colour intensity correspond to different types of surface epithelium. Stereomicroscopy, however, did not show differences between various histological types of anal canal carcinoma.