Malignant neoplasm of appendix vermiformis

This code signifies a primary cancerous tumor originating in the appendix. It refers to the uncontrolled growth of abnormal cells within the vermiform appendix, which is a small, finger-shaped organ projecting from the large intestine.

Assign this code when documentation confirms a malignant neoplasm of the appendix. This diagnosis is typically made following surgical resection and pathological examination of the appendiceal tissue. It is often an incidental finding during appendectomy performed for suspected appendicitis.

• Differentiate between primary appendiceal malignancy and metastatic disease to the appendix.
• Ensure the pathology report explicitly states "malignant neoplasm" of the appendix.
• Consider sequencing rules if the appendiceal cancer is a secondary site from another primary malignancy.