ICD-10 Code C50.422 – Malignant neoplasm of upper-outer quadrant of left male breast (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C50.422 – Malignant neoplasm of upper-outer quadrant of left male breast
What it is
This code identifies a malignant tumor located in the upper-outer quadrant of the left male breast. Use it when documentation specifies both the left side and the upper-outer breast quadrant.
Clinical signs
Typical findings may include a palpable breast mass, skin or nipple changes, or enlarged regional lymph nodes. Clinical features vary; refer to documentation.
When to use this code
Use C50.422 when the provider documents primary breast cancer in the upper-outer quadrant of the left breast in a male patient. It also fits when imaging, pathology, or the final diagnosis clearly localize the malignancy to that site. Check documentation if the laterality or quadrant is not stated.
Do not use for
Do not use this code for benign breast lesions, metastatic disease to the breast, or unspecified breast cancer location. If the record does not confirm the left upper-outer quadrant, choose a more specific or unspecified code as supported by documentation.
Coding tip
Confirm both anatomic site and laterality in the pathology or final provider note before assigning C50.422.