ICD-10 Code D41.1 – Neoplasm of uncertain behavior of renal pelvis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D41.1 – Neoplasm of uncertain behavior of renal pelvis
What it is
D41.1 identifies a renal pelvis growth whose behavior is not clearly benign or malignant. Use it when the record documents an uncertain neoplasm arising in the renal pelvis.
Clinical signs
Clinical features vary; refer to documentation. Patients may be evaluated for a renal pelvis mass or lesion found on imaging, endoscopy, or pathology, but the code is based on the documented diagnosis, not symptoms alone.
When to use this code
Use D41.1 when the provider specifically documents a neoplasm of uncertain behavior in the renal pelvis. Code it for confirmed uncertain or borderline behavior when malignancy and benignity are not established.
Choose this code when the anatomic site is the renal pelvis and the record does not support a more specific malignant or benign neoplasm code. Check documentation if the site or behavior is unclear.
Do not use for
Do not use D41.1 for malignant neoplasms of the renal pelvis or for benign renal pelvis lesions documented as such. Check documentation if the note only describes a mass without a stated behavior.
Coding tip
Verify both site and behavior in the report before assigning D41.1.