ICD-10 Code C24.1 – Malignant neoplasm of ampulla of Vater (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C24.1 – Malignant neoplasm of ampulla of Vater
What it is
This code identifies a malignant tumor arising in the ampulla of Vater, where the bile duct and pancreatic duct empty into the duodenum. Use it when documentation confirms a primary cancer at that site.
Clinical signs
Common findings include painless jaundice, dark urine, pale stools, pruritus, and possible weight loss. Endoscopic, imaging, or pathology reports may show an ampullary mass; clinical features vary, refer to documentation.
When to use this code
Use C24.1 when the provider documents primary malignancy of the ampulla of Vater, including ampullary carcinoma. It also applies when the diagnosis is confirmed by pathology, imaging, or operative findings and the site is clearly stated. If the record only says periampullary or pancreatic head cancer, check documentation.
Do not use for
Do not use this code for benign ampullary tumors, inflammatory obstruction, or unspecified biliary or pancreatic cancers. If the primary site is unclear, check documentation before assigning C24.1.
Coding tip
Confirm that the ampulla of Vater is named as the primary site, not just a nearby structure or metastatic disease.