ICD-10 Code C50.412 – Malignant neoplasm of upper-outer quadrant of left female breast (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C50.412 – Malignant neoplasm of upper-outer quadrant of left female breast
What it is
This code identifies a malignant tumor in the upper-outer quadrant of the left breast in a female patient. Use it when documentation specifies both the breast quadrant and left-sided location.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include a palpable breast mass, skin or nipple changes, or imaging and biopsy results confirming malignancy in the specified quadrant.
When to use this code
Use C50.412 when the record clearly states primary breast cancer in the upper-outer quadrant of the left female breast. It is appropriate for confirmed malignancy, including pathology or specialist documentation that identifies this exact site. Check documentation if the site is described more generally.
Do not use for
Do not use this code for benign breast disease, unspecified breast cancer sites, or lesions in a different breast quadrant. If the laterality or quadrant is not documented, check documentation before coding.
Coding tip
Verify both laterality and quadrant in the pathology, imaging, or oncology note before assigning this code.