Malignant carcinoid tumor of the ascending colon

This code identifies a primary neuroendocrine tumor originating in the ascending colon, characterized by its malignant nature. These tumors arise from enterochromaffin cells and can produce various bioactive substances, leading to carcinoid syndrome in some cases.

Assign this code when documentation confirms a malignant carcinoid tumor specifically located in the ascending colon. This diagnosis is typically established through biopsy and histopathological examination. Use this code for initial diagnosis and subsequent encounters related to the management of this specific primary tumor.

• Ensure the documentation explicitly states "malignant" and specifies the ascending colon as the primary site.
• Distinguish from benign carcinoid tumors (D3A.022) and carcinoid tumors of unspecified behavior (D3A.8).
• Code any associated carcinoid syndrome (E34.0) separately, following sequencing guidelines.