| C4A51 | Merkel cell carcinoma of anal skin |
| C4A52 | Merkel cell carcinoma of skin of breast |
| C4A59 | Merkel cell carcinoma of other part of trunk |
| C4A6 | Merkel cell carcinoma of upper limb, including shoulder |
| C4A60 | Merkel cell carcinoma of unsp upper limb, including shoulder Merkel cell carcinoma of unspecified upper limb, including shoulder |
| C4A61 | Merkel cell carcinoma of right upper limb, including shoulder |
| C4A62 | Merkel cell carcinoma of left upper limb, including shoulder Merkel cell carcinoma of left upper limb, including shoulder |
| C4A7 | Merkel cell carcinoma of lower limb, including hip |
| C4A70 | Merkel cell carcinoma of unspecified lower limb, including hip |
| C4A71 | Merkel cell carcinoma of right lower limb, including hip |
| C4A72 | Merkel cell carcinoma of left lower limb, including hip |
| C4A8 | Merkel cell carcinoma of overlapping sites |
| C4A9 | Merkel cell carcinoma, unspecified |
| C50 | Malignant neoplasm of breast |
| C500 | Malignant neoplasm of nipple and areola |
| C5001 | Malignant neoplasm of nipple and areola, female |
| C50011 | Malignant neoplasm of nipple and areola, right female breast Malignant neoplasm of nipple and areola, right female breast |
| C50012 | Malignant neoplasm of nipple and areola, left female breast |
| C50019 | Malignant neoplasm of nipple and areola, unspecified female breast |
| C5002 | Malignant neoplasm of nipple and areola, male |
| C50021 | Malignant neoplasm of nipple and areola, right male breast |
| C50022 | Malignant neoplasm of nipple and areola, left male breast |
| C50029 | Malignant neoplasm of nipple and areola, unspecified male breast |
| C501 | Malignant neoplasm of central portion of breast |
| C5011 | Malignant neoplasm of central portion of breast, female |
| C50111 | Malignant neoplasm of central portion of right female breast Malignant neoplasm of central portion of right female breast |
| C50112 | Malignant neoplasm of central portion of left female breast |
| C50119 | Malignant neoplasm of central portion of unspecified female breast |
| C5012 | Malignant neoplasm of central portion of breast, male |
| C50121 | Malignant neoplasm of central portion of right male breast |
| C50122 | Malignant neoplasm of central portion of left male breast |
| C50129 | Malignant neoplasm of central portion of unspecified male breast |
| C502 | Malignant neoplasm of upper-inner quadrant of breast |
| C5021 | Malignant neoplasm of upper-inner quadrant of breast, female Malignant neoplasm of upper-inner quadrant of breast, female |
| C50211 | Malignant neoplasm of upper-inner quadrant of right female breast |
| C50212 | Malig neoplasm of upper-inner quadrant of left female breast Malignant neoplasm of upper-inner quadrant of left female breast |
| C50219 | Malig neoplasm of upper-inner quadrant of unsp female breast Malignant neoplasm of upper-inner quadrant of unspecified female breast |
| C5022 | Malignant neoplasm of upper-inner quadrant of breast, male |
| C50221 | Malignant neoplasm of upper-inner quadrant of right male breast |
| C50222 | Malignant neoplasm of upper-inner quadrant of left male breast |
| C50229 | Malignant neoplasm of upper-inner quadrant of unspecified male breast |
| C503 | Malignant neoplasm of lower-inner quadrant of breast |
| C5031 | Malignant neoplasm of lower-inner quadrant of breast, female Malignant neoplasm of lower-inner quadrant of breast, female |
| C50311 | Malignant neoplasm of lower-inner quadrant of right female breast |
| C50312 | Malig neoplasm of lower-inner quadrant of left female breast Malignant neoplasm of lower-inner quadrant of left female breast |
| C50319 | Malig neoplasm of lower-inner quadrant of unsp female breast Malignant neoplasm of lower-inner quadrant of unspecified female breast |
| C5032 | Malignant neoplasm of lower-inner quadrant of breast, male |
| C50321 | Malignant neoplasm of lower-inner quadrant of right male breast |
| C50322 | Malignant neoplasm of lower-inner quadrant of left male breast |
| C50329 | Malignant neoplasm of lower-inner quadrant of unspecified male breast |