ICD-10 Code C16.4 – Malignant neoplasm of pylorus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C16.4 – Malignant neoplasm of pylorus
What it is
C16.4 identifies a malignant tumor arising in the pylorus, the lower part of the stomach that empties into the duodenum. Use it when documentation specifies a primary cancer of the pyloric region.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings in gastric cancer include upper abdominal pain, early satiety, weight loss, nausea, vomiting, or outlet obstruction when the pylorus is involved.
When to use this code
Use C16.4 when the provider documents a primary malignant neoplasm of the pylorus, including “pyloric cancer” or “gastric cancer of the pylorus.” Code it from confirmed diagnostic documentation, pathology, or definitive specialist assessment. If the record only says stomach cancer without location, check documentation.
Do not use for
Do not use this code for benign pyloric disease, ulcers, or nonspecific gastric malignancy without a pyloric site. Also avoid it when the cancer is documented in another stomach subsite.
Coding tip
Verify the exact anatomic site in the pathology or operative note before assigning C16.4.