Neoplasm of uncertain behavior of unspecified testis

This code signifies a testicular mass or lesion that pathologists have identified as having an uncertain potential for malignancy. It indicates that the cellular characteristics are not definitively benign nor definitively malignant, requiring further investigation or monitoring.

Assign this code when pathology reports describe a testicular neoplasm as "uncertain behavior," "borderline," or "of unknown malignant potential" and the specific testis (left or right) is not documented. This is often an interim diagnosis while awaiting further diagnostic clarity or during follow-up.

• Ensure the pathology report explicitly states "uncertain behavior" or similar terminology; do not assume based on clinical suspicion alone.
• If the laterality of the testis is specified (left or right), use the more specific codes D40.11 or D40.12.
• Do not use this code for neoplasms definitively diagnosed as benign (e.g., adenoma) or malignant (e.g., carcinoma in situ).