ICD-10 Code C50.42 – Malignant neoplasm of upper-outer quadrant of breast, male (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C50.42 – Malignant neoplasm of upper-outer quadrant of breast, male
What it is
This code identifies a malignant tumor arising in the upper-outer quadrant of the male breast. It is used when documentation specifies that breast cancer is located in that quadrant.
Clinical signs
Clinical features may include a palpable breast mass, nipple changes, skin dimpling, or localized breast pain. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents primary breast cancer in the upper-outer quadrant of the male breast. It may appear in pathology, imaging, or oncology notes that clearly identify the site. If the record only says “breast cancer” without a quadrant, check documentation.
Do not use for
Do not use this code for benign breast lesions, unspecified breast malignancy, or cancer in another breast quadrant. Check documentation if the site is unclear or if the lesion is metastatic rather than primary.
Coding tip
Verify laterality and exact quadrant from the pathology or provider note before assigning C50.42.