ICD-10 Code C50.919 – Malignant neoplasm of unspecified site of unspecified female breast (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C50.919 – Malignant neoplasm of unspecified site of unspecified female breast
What it is
This code identifies a malignant breast tumor in a female patient when the site within the breast is not specified. Use it when the record confirms breast cancer but does not document a more exact location.
Clinical signs
Clinical features vary; refer to documentation. Breast cancer may be noted as a palpable mass, abnormal imaging finding, nipple change, skin dimpling, or biopsy-proven malignancy.
When to use this code
Use C50.919 when the provider documents malignant neoplasm of the female breast but does not identify the quadrant, subsite, or laterality details needed for a more specific code. It is appropriate for confirmed cancer diagnoses, not for screening or benign breast conditions. If the chart later specifies the site, code to the more precise breast cancer code.
Do not use for
Do not use this code for male breast cancer, benign breast disease, or breast screening findings. Check documentation if the lesion is described as uncertain, in situ, or metastatic from another primary site.
Coding tip
Query for exact breast site and laterality before settling on C50.919.