| C50.31 | Malignant neoplasm of lower-inner quadrant of breast, female | NON-BILLABLE CODE |
| C50.311 | Malignant neoplasm of lower-inner quadrant of right female breast | BILLABLE CODE |
| C50.312 | Malignant neoplasm of lower-inner quadrant of left female breast | BILLABLE CODE |
| C50.319 | Malignant neoplasm of lower-inner quadrant of unspecified female breast | BILLABLE CODE |
| C50.32 | Malignant neoplasm of lower-inner quadrant of breast, male | NON-BILLABLE CODE |
| C50.321 | Malignant neoplasm of lower-inner quadrant of right male breast | BILLABLE CODE |
| C50.322 | Malignant neoplasm of lower-inner quadrant of left male breast | BILLABLE CODE |
| C50.329 | Malignant neoplasm of lower-inner quadrant of unspecified male breast | BILLABLE CODE |
