Malignant neoplasm of ureter (C66)

The ICD-10 code C66 and its subcodes identify malignant tumors located in the ureter, the tube that carries urine from the kidneys to the bladder. These codes specify whether the cancer affects the right ureter (C66.1), left ureter (C66.2), or an unspecified ureter (C66.9).

These codes are used to classify cancers such as transitional cell carcinoma; also known as primary transitional cell carcinoma of the ureter or upper urinary tract; that originate in the lining of the ureter. The detailed subcodes help healthcare providers and medical coders indicate the exact location of the malignancy for accurate diagnosis, treatment planning, and billing. For example, C66.1 is assigned for malignant neoplasm of the right ureter, while C66.2 applies to the left ureter. When the specific ureter is not documented, C66.9 is appropriate. This section of ICD-10 applies specifically to urinary system cancers involving the ureter and helps distinguish these from other genitourinary malignancies. Using the correct code ensures proper clinical communication and data tracking for ureter cancers.