C21: Malignant neoplasm of anus and anal canal

malignant carcinoid tumors of the colon (C7A.02-)
malignant melanoma of anal margin (C43.51)
malignant melanoma of anal skin (C43.51)
malignant melanoma of perianal skin (C43.51)
other and unspecified malignant neoplasm of anal margin (C44.500, C44.510, C44.520, C44.590)
other and unspecified malignant neoplasm of anal skin (C44.500, C44.510, C44.520, C44.590)
other and unspecified malignant neoplasm of perianal skin (C44.500, C44.510, C44.520, C44.590)