ICD-10-CM > C00-D49 > C50-C50 > C50 > C50.4 > C50.42 C50.42 Malignant neoplasm of upper-outer quadrant of breast, male Non-Billable/Non-Specific Codes C50.421Malignant neoplasm of upper-outer quadrant of right male breastC50.422Malignant neoplasm of upper-outer quadrant of left male breastC50.429Malignant neoplasm of upper-outer quadrant of unspecified male breast