Malignant neoplasm of axillary tail of left male breast

This code signifies a cancerous tumor originating in the axillary tail (tail of Spence) of the left breast in a male patient. This specific anatomical location is an extension of breast tissue into the axilla.

Apply this code when documentation confirms a primary malignant neoplasm in the axillary tail of the left male breast. This diagnosis is typically established through biopsy and pathology reports.

• Ensure the documentation explicitly states "male breast" and "left" side.
• Verify that the tumor is specifically located in the "axillary tail" and not another quadrant of the breast.
• Always sequence this code as the primary diagnosis when it represents the reason for the encounter.