C18.4

Billable

Malignant neoplasm of transverse colon

HCC Category Mapping

V28HCC 22 — Colorectal, Bladder, and Other Cancers

0.000

V24HCC 11 — Colorectal, Bladder, and Other Cancers

0.306

ESRDHCC 11 — Colorectal, Bladder, and Other Cancers

0.000

What This Code Means

Cancer that starts in the transverse colon, which is the part of the large intestine that runs horizontally across the upper abdomen.

Coding Tips

•Verify the exact anatomical location is documented as transverse colon to distinguish from other colon segments
•Ensure histological type and stage are documented separately, as they are not included in this code

Clinical Significance

Malignant neoplasm of the transverse colon occurs in the horizontal segment of the large intestine that crosses the upper abdomen. The transverse colon represents a transitional zone between right-sided and left-sided colon cancers, and its molecular profile may have features of either. This location requires specific surgical planning, often involving extended colectomy to ensure adequate lymph node harvest and clear margins.

Documentation Requirements

✓Documentation confirming transverse colon as the tumor location
✓Histological type and grade
✓Stage of disease
✓Whether the tumor is in the proximal, mid, or distal transverse colon (affects surgical approach)
✓Colonoscopy or imaging confirmation

Commonly Confused Codes

C18.3 — Hepatic flexure: the proximal end of the transverse colon starts after the hepatic flexure C18.5 — Splenic flexure: the distal end of the transverse colon transitions to the splenic flexure C18.8 — Overlapping sites: use when the tumor clearly spans the transverse colon into an adjacent segment

Code Hierarchy

└C18Malignant neoplasm of colon └C18.4Malignant neoplasm of transverse colon

└C18.4Malignant neoplasm of transverse colon