C17.9

HCC Category Mapping

What This Code Means

This code represents cancer that has developed in the small intestine, but the specific location within the small intestine (duodenum, jejunum, or ileum) has not been identified or documented. It is used when a patient has been diagnosed with small intestine cancer without more specific anatomical detail.

Coding Tips

• •Query the physician if the specific site of the small intestine cancer is documented in the medical record, as codes C17.0 (duodenum), C17.1 (jejunum), and C17.2 (ileum) provide more specificity and may affect treatment planning and staging
• •Ensure this code is used only when the site is truly unspecified; review pathology reports and imaging studies which often document the exact location of the malignancy

Clinical Significance

Unspecified small intestine cancer is used when documentation confirms malignancy but does not identify which segment (duodenum, jejunum, or ileum) is involved. Small bowel cancers are rare overall, accounting for less than 5% of gastrointestinal malignancies, but carry significant morbidity. While this code captures the appropriate HCC, documentation improvement efforts should aim to identify the specific segment from surgical, pathological, or imaging records.

Documentation Requirements

• ✓Confirmed malignancy of the small intestine
• ✓Review of all available records (pathology, operative notes, imaging) for segment identification before defaulting to unspecified
• ✓Histological type if known
• ✓Stage of disease
• ✓Treatment status

Commonly Confused Codes