ICD-10 Code C50.2 – Malignant neoplasm of upper-inner quadrant of breast (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C50.2 – Malignant neoplasm of upper-inner quadrant of breast
What it is
C50.2 identifies a malignant breast tumor located in the upper-inner quadrant. Use it when documentation specifies this breast subsite and confirms a cancer diagnosis.
Clinical signs
Findings may include a breast mass, skin or nipple changes, or abnormal imaging that leads to biopsy confirmation. Clinical features vary; refer to documentation.
When to use this code
Use C50.2 when the provider documents primary malignant neoplasm in the upper-inner quadrant of the breast. It is appropriate for confirmed breast cancer at that specific site, whether newly diagnosed or under active evaluation. If the record only says “breast cancer” without a quadrant, check documentation.
Do not use for
Do not use this code for benign breast disease, metastatic disease to the breast, or unspecified breast location. If the quadrant is not documented, choose a more specific or unspecified code only when supported.
Coding tip
Verify laterality and exact breast subsite in the pathology, imaging, or provider note before assigning C50.2.