ICD-10 Code D41.12 – Neoplasm of uncertain behavior of left renal pelvis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D41.12 – Neoplasm of uncertain behavior of left renal pelvis
What it is
This code identifies a growth in the left renal pelvis whose behavior is uncertain, meaning the pathology cannot yet classify it as clearly benign or malignant. Use it for documented neoplasms in that specific site when final behavior is not established.
Clinical signs
Clinical features vary; refer to documentation. Patients may have imaging or endoscopic findings of a renal pelvis mass, hematuria, or obstruction, but the code is based on the documented uncertain neoplasm rather than symptoms alone.
When to use this code
Use D41.12 when the provider documents a neoplasm of uncertain behavior in the left renal pelvis and no more specific malignant or benign diagnosis is confirmed. It is appropriate for pathology reports or specialist notes stating uncertain behavior. If the record later specifies a different behavior or site, code the final documented diagnosis.
Do not use for
Do not use this code for clearly malignant renal pelvis tumors, benign lesions, or nonspecific hematuria without a documented neoplasm. Check documentation if the left-sided site or uncertain behavior is not explicitly stated.
Coding tip
Verify both the laterality and the phrase “uncertain behavior” in the record before assigning D41.12.