In simple words: This code indicates cancer in one of the kidneys, but the doctor's records don't specify whether it's the right or left kidney. It's important to note that this code doesn't apply if the cancer is in the part of the kidney where urine collects (renal pelvis).

This code represents a cancerous growth in a kidney, but the specific kidney (right or left) is not identified in the medical documentation.It excludes cancers of the renal pelvis, which are coded separately.

Example 1: A patient presents with flank pain, blood in their urine, and weight loss. Imaging reveals a mass in the kidney, biopsy confirms malignancy. As laterality isn't specified in the report, C64.9 is used., During a routine physical, a mass is discovered incidentally on a patient's kidney via ultrasound. Biopsy later confirms renal cell carcinoma, however, the report fails to specify whether the affected kidney is the left or right.C64.9 is used., A patient with a history of long-term dialysis experiences worsening anemia and fatigue. Imaging shows a suspicious lesion on one kidney, subsequently biopsied and confirmed as cancerous, however the side isn't mentioned on the path report so C64.9 is appropriate.

Documentation must confirm the malignancy and its location within the kidney (excluding the renal pelvis).If the affected kidney (right or left) is known, that should be documented as well. The diagnostic process, including imaging, biopsy findings, and other pertinent clinical information should be thoroughly documented.