Malignant neoplasm of unspecified round ligament

This code signifies a cancerous tumor originating in an unspecified round ligament. These ligaments are fibrous bands that support organs, such as the round ligament of the uterus or the round ligament of the liver. The malignancy is primary, meaning it originated in the ligament itself, and the specific round ligament involved is not documented.

Use this code when documentation confirms a primary malignant neoplasm of a round ligament, but the specific anatomical location (e.g., uterine, hepatic) is not specified. This code is appropriate when pathology reports confirm malignancy and the physician's diagnosis points to a round ligament, but further detail is lacking.

• Avoid using this code if the specific round ligament is identified; instead, use a more precise code from the C57 series (e.g., C57.21 for uterine round ligament).
• Ensure documentation clearly states "malignant neoplasm" and not a benign or uncertain tumor.
• Sequence this code as the primary diagnosis if the malignancy is the reason for the encounter and no other primary site is identified.