ICD-10 Code D37.4 – Neoplasm of uncertain behavior of colon (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D37.4 – Neoplasm of uncertain behavior of colon
What it is
D37.4 identifies a colon neoplasm whose behavior cannot be determined from current information. It is used when the lesion is not clearly documented as benign or malignant.
Clinical signs
Clinical features vary; refer to documentation. Patients may have an incidental colon mass, polyp, or lesion found on imaging, endoscopy, or pathology when the biologic behavior remains uncertain.
When to use this code
Use D37.4 when the provider documents an uncertain or indeterminate neoplasm of the colon and no definitive malignant or benign diagnosis is established. It fits cases awaiting pathology, further workup, or specialist review. Code the documented site as colon, not rectum or other bowel segments.
Do not use for
Do not use this code for confirmed malignant colon neoplasms, benign polyps, or inflammatory bowel conditions. Check documentation if the lesion is described as carcinoma, adenoma, or another specific diagnosis.
Coding tip
Assign D37.4 only when the record supports uncertainty about behavior, not just uncertainty about symptoms or treatment.