ICD-10 Code C50.912 – Malignant neoplasm of unspecified site of left female breast (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C50.912 – Malignant neoplasm of unspecified site of left female breast
What it is
C50.912 identifies a malignant breast tumor in the left female breast when the exact quadrant or site is not documented. Use it for confirmed cancer, not for benign or high-risk breast findings.
Clinical signs
Findings may include a palpable breast mass, abnormal imaging, nipple changes, skin dimpling, or biopsy-confirmed malignancy. Clinical features vary; refer to documentation.
When to use this code
Use this code when the record clearly states left female breast cancer but does not specify the exact breast site. It also fits when pathology or oncology notes confirm malignancy and laterality, yet the subsite remains unspecified. Check documentation if the lesion location is unclear.
Do not use for
Do not use this code for benign breast disease, carcinoma in situ, or male breast cancer. If the documentation names a specific left breast quadrant, code that more precise site instead.
Coding tip
Verify laterality and whether the provider documented a more specific breast subsite before assigning C50.912.