ICD-10 Code C50.512 – Malignant neoplasm of lower-outer quadrant of left female breast (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C50.512 – Malignant neoplasm of lower-outer quadrant of left female breast
What it is
This code identifies a malignant tumor located in the lower-outer quadrant of the left female breast. Use it when the record specifies both the left side and the lower-outer breast location.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include a palpable breast mass, breast asymmetry, skin or nipple changes, or imaging and biopsy evidence confirming malignancy.
When to use this code
Use C50.512 when the provider documents primary breast cancer in the lower-outer quadrant of the left female breast. It is appropriate when pathology, imaging, or operative notes clearly identify this exact anatomic site. If the laterality or quadrant is not documented, check documentation before coding.
Do not use for
Do not use this code for benign breast masses, carcinoma in situ, or unspecified breast cancer. Also avoid it when the tumor site is different or the record does not confirm the left lower-outer quadrant.
Coding tip
Verify both laterality and quadrant in the pathology or oncology note before assigning C50.512.