ICD-10 Code C18.5 – Malignant neoplasm of splenic flexure (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C18.5 – Malignant neoplasm of splenic flexure
What it is
C18.5 identifies a malignant tumor arising in the splenic flexure, the bend of the colon near the spleen. Use it when documentation specifies primary colon cancer at this exact site.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings include a confirmed colon mass, biopsy-proven malignancy, or imaging showing a tumor at the splenic flexure.
When to use this code
Use C18.5 when the provider documents primary cancer of the splenic flexure or a malignant neoplasm located at that colonic segment. It is also appropriate when pathology or operative notes identify the splenic flexure as the primary site. Check documentation if the record only says left colon, transverse colon, or colon cancer without a precise location.
Do not use for
Do not use this code for benign polyps, carcinoma in situ, or metastatic disease to the colon from another primary site. If the exact site is unclear, check documentation.
Coding tip
Code the documented primary site exactly; splenic flexure is not interchangeable with other colon segments.