ICD-10 Code C50.629 – Malignant neoplasm of axillary tail of unspecified male breast (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C50.629 – Malignant neoplasm of axillary tail of unspecified male breast
What it is
This code identifies a malignant tumor arising in the axillary tail of the male breast when the side is not specified. Use it for documented breast cancer in that tissue region, not for benign breast conditions.
Clinical signs
Clinical features vary; refer to documentation. Commonly, records note a palpable breast or axillary-tail mass, possible skin or nipple changes, or imaging and biopsy findings confirming malignancy.
When to use this code
Use this code when the provider documents primary breast cancer in the axillary tail and does not specify right or left. It is also appropriate when pathology or oncology notes confirm the site as the axillary tail of the unspecified male breast. Check documentation if laterality is available elsewhere.
Do not use for
Do not use this code for benign breast masses, inflammatory breast disorders, or cancers in a different breast location. If the record specifies right or left side, use the laterality-specific code instead.
Coding tip
Verify the anatomic site and laterality in the operative, pathology, or oncology note before assigning this code.