ICD-10-CM > C00-D49 > C15-C26 > C26 C26 Malignant neoplasm of other and ill-defined digestive organs Non-Billable/Non-Specific Type 1 Excludes malignant neoplasm of peritoneum and retroperitoneum (C48.-) Codes C26.0Malignant neoplasm of intestinal tract, part unspecifiedC26.1Malignant neoplasm of spleenC26.9Malignant neoplasm of ill-defined sites within the digestive system