ICD-10 Code C50.621 – Malignant neoplasm of axillary tail of right male breast (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C50.621 – Malignant neoplasm of axillary tail of right male breast
What it is
C50.621 identifies a malignant tumor arising in the axillary tail of the right breast in a male patient. Use it when documentation specifies this exact breast subsite and laterality.
Clinical signs
Typical findings include a palpable mass in the upper outer breast or axillary tail, with possible skin or tissue distortion. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents primary breast cancer in the axillary tail of the right male breast. It is appropriate for confirmed malignant neoplasm at this exact site, including pathology-based diagnoses. If the record only states breast cancer without location, check documentation.
Do not use for
Do not use it for benign breast masses, unspecified breast cancer, or disease in the left breast. Do not assign it when the site is not documented or when the lesion is metastatic to the breast.
Coding tip
Verify both laterality and exact anatomic site in the note before assigning C50.621.