Fig. 5From: A case of metastatic carcinoma of anal fistula caused by implantation from rectal cancerImmunohistochemical staining (×20). Rectum lesion stained CK7 (−) (a) CK20 (+) (b) and the fistula stained CK7 (−) (c) and CK20 (+) (d) Back to article page