C18.7
BillableMalignant neoplasm of sigmoid colon
HCC Category Mapping
V28HCC 22 — Colorectal, Bladder, and Other Cancers
0.000V24HCC 11 — Colorectal, Bladder, and Other Cancers
0.306ESRDHCC 11 — Colorectal, Bladder, and Other Cancers
0.000What This Code Means
Cancer that develops in the sigmoid colon, which is the S-shaped section of the large intestine located in the lower left abdomen just before the rectum.
Coding Tips
- •Sigmoid colon cancer is one of the most common colorectal cancer locations; verify it does not extend to the rectum
- •If the tumor involves both sigmoid colon and rectum, use C19 (rectosigmoid junction) instead
Clinical Significance
Malignant neoplasm of the sigmoid colon is one of the most common colorectal cancer locations, occurring in the S-shaped segment of the colon in the lower left abdomen just proximal to the rectum. Sigmoid cancers are classified as left-sided colon cancers with favorable molecular profiles for anti-epidermal growth factor receptor therapy. These tumors frequently present with changes in bowel habits, rectal bleeding, or partial obstruction due to the relatively narrow sigmoid lumen.
Documentation Requirements
- ✓Documentation confirming sigmoid colon as the tumor location
- ✓Histological type and grade
- ✓Stage of disease (TNM staging)
- ✓Distinction from rectosigmoid junction involvement
- ✓Molecular markers (KRAS, NRAS, BRAF, microsatellite instability status) if tested
Excludes 1 — Do NOT code together
- malignant neoplasm of rectosigmoid junction (C19)
Commonly Confused Codes
C19 — Rectosigmoid junction: if the tumor involves the junction between sigmoid and rectum, use C19 insteadC18.6 — Descending colon: the descending colon is proximal to the sigmoid; verify documentation specifies the S-shaped portionC20 — Rectum: sigmoid cancers that extend into the rectum may need to be coded as rectosigmoid (C19) depending on the epicenter
Code Hierarchy
└C18Malignant neoplasm of colon└C18.7Malignant neoplasm of sigmoid colon
└C18.7Malignant neoplasm of sigmoid colon