ICD-10 Code C50.612 – Malignant neoplasm of axillary tail of left female breast (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C50.612 – Malignant neoplasm of axillary tail of left female breast
What it is
This code identifies a malignant breast tumor located in the axillary tail of the left female breast. Use it when documentation specifies this exact anatomic site and laterality.
Clinical signs
Clinical features vary; refer to documentation. Commonly, records describe a breast or axillary tail mass, abnormal imaging, or biopsy-confirmed malignancy.
When to use this code
Use C50.612 when the provider documents primary cancer in the axillary tail of the left female breast. It is appropriate for confirmed malignant neoplasm and for encounters focused on this specific site. Check documentation if the record only says “breast cancer” without laterality or location.
Do not use for
Do not use this code for benign breast disease, metastatic disease to the breast, or unspecified breast cancer. If the site is not clearly documented as the left axillary tail, check documentation.
Coding tip
Verify both laterality and exact breast subsite before assigning C50.612.