| C169 | Malignant neoplasm of stomach, unspecified |
| C17 | Malignant neoplasm of small intestine |
| C170 | Malignant neoplasm of duodenum |
| C171 | Malignant neoplasm of jejunum |
| C172 | Malignant neoplasm of ileum |
| C173 | Meckel's diverticulum, malignant |
| C178 | Malignant neoplasm of overlapping sites of small intestine |
| C179 | Malignant neoplasm of small intestine, unspecified |
| C18 | Malignant neoplasm of colon |
| C180 | Malignant neoplasm of cecum |
| C181 | Malignant neoplasm of appendix |
| C182 | Malignant neoplasm of ascending colon |
| C183 | Malignant neoplasm of hepatic flexure |
| C184 | Malignant neoplasm of transverse colon |
| C185 | Malignant neoplasm of splenic flexure |
| C186 | Malignant neoplasm of descending colon |
| C187 | Malignant neoplasm of sigmoid colon |
| C188 | Malignant neoplasm of overlapping sites of colon |
| C189 | Malignant neoplasm of colon, unspecified |
| C19 | Malignant neoplasm of rectosigmoid junction |
| C20 | Malignant neoplasm of rectum |
| C21 | Malignant neoplasm of anus and anal canal |
| C210 | Malignant neoplasm of anus, unspecified |
| C211 | Malignant neoplasm of anal canal |
| C212 | Malignant neoplasm of cloacogenic zone |
| C218 | Malig neoplasm of ovrlp sites of rectum, anus and anal canal Malignant neoplasm of overlapping sites of rectum, anus and anal canal |
| C22 | Malignant neoplasm of liver and intrahepatic bile ducts |
| C220 | Liver cell carcinoma |
| C221 | Intrahepatic bile duct carcinoma |
| C222 | Hepatoblastoma |
| C223 | Angiosarcoma of liver |
| C224 | Other sarcomas of liver |
| C227 | Other specified carcinomas of liver |
| C228 | Malignant neoplasm of liver, primary, unspecified as to type Malignant neoplasm of liver, primary, unspecified as to type |
| C229 | Malignant neoplasm of liver, not specified as primary or secondary |
| C23 | Malignant neoplasm of gallbladder |
| C24 | Malignant neoplasm of other and unspecified parts of biliary tract |
| C240 | Malignant neoplasm of extrahepatic bile duct |
| C241 | Malignant neoplasm of ampulla of Vater |
| C248 | Malignant neoplasm of overlapping sites of biliary tract |
| C249 | Malignant neoplasm of biliary tract, unspecified |
| C25 | Malignant neoplasm of pancreas |
| C250 | Malignant neoplasm of head of pancreas |
| C251 | Malignant neoplasm of body of pancreas |
| C252 | Malignant neoplasm of tail of pancreas |
| C253 | Malignant neoplasm of pancreatic duct |
| C254 | Malignant neoplasm of endocrine pancreas |
| C257 | Malignant neoplasm of other parts of pancreas |
| C258 | Malignant neoplasm of overlapping sites of pancreas |
| C259 | Malignant neoplasm of pancreas, unspecified |