ICD-10 Code D48.6 – Neoplasm of uncertain behavior of breast (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D48.6 – Neoplasm of uncertain behavior of breast
What it is
D48.6 identifies a breast mass or lesion whose behavior is uncertain. Use it when pathology or clinical evaluation cannot yet classify the growth as clearly benign or malignant.
Clinical signs
Clinical features vary; refer to documentation. Findings may include a palpable breast lump, imaging abnormality, or biopsy result that does not confirm benign or malignant behavior.
When to use this code
Use this code when the record specifically describes an uncertain or borderline neoplasm of the breast. It may apply during workup, after biopsy, or when the pathologist documents uncertain behavior. If the site or behavior is unclear, check documentation before assigning the code.
Do not use for
Do not use D48.6 for clearly benign breast lesions or confirmed breast cancer. If the diagnosis is inflammatory, cystic, or otherwise non-neoplastic, choose the more specific documented condition.
Coding tip
Code the breast lesion only when the provider documents uncertain behavior; otherwise, query for clarification.