ICD-10 Code D49.519 – Neoplasm of unspecified behavior of unspecified kidney (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D49.519 – Neoplasm of unspecified behavior of unspecified kidney
What it is
D49.519 identifies a kidney mass or growth whose behavior is not clearly documented as benign or malignant. Use it when the record says “unspecified behavior” and the kidney is the site, but the exact nature is not established.
Clinical signs
Clinical features vary; refer to documentation. Patients may have an incidental renal mass on imaging or nonspecific findings such as flank pain or hematuria, but the code itself reflects uncertain behavior, not a confirmed diagnosis.
When to use this code
Use this code when the provider documents a neoplasm of the kidney with unspecified behavior, or when pathology and imaging have not yet clarified whether the lesion is benign or malignant. It is appropriate for incomplete workup or ambiguous wording in the chart. Check documentation if the lesion is later specified.
Do not use for
Do not use D49.519 for clearly benign renal cysts or confirmed malignant kidney tumors. If the record identifies a specific renal neoplasm type or behavior, code that diagnosis instead.
Coding tip
Match the code to the provider’s exact wording; “unspecified behavior” must be documented, not assumed.