Malignant neoplasm of axillary tail of unsp female breast

This code signifies a primary cancerous tumor originating in the axillary tail (tail of Spence) of a female breast, where the specific side (left or right) is not documented. This is a malignant growth requiring definitive diagnosis and treatment.

Apply this code when documentation confirms a primary malignant neoplasm located in the axillary tail of a female breast, and the medical record does not specify laterality. This typically occurs when pathology reports or imaging studies identify the tumor's location but omit the specific breast side.

• Ensure the documentation explicitly states "axillary tail" and "female breast."
• Do not use this code if laterality (left or right breast) is specified; instead, select the more specific C50.611 or C50.612.
• Always sequence this code as the primary diagnosis when it represents the reason for the encounter, followed by any relevant secondary diagnoses.