ICD-10 Code D00.1 – Carcinoma in situ of esophagus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D00.1 – Carcinoma in situ of esophagus
What it is
D00.1 identifies carcinoma in situ of the esophagus, meaning abnormal cells are confined to the lining and have not invaded deeper tissue. Use it when the record clearly states an in situ esophageal malignancy.
Clinical signs
Clinical features vary; refer to documentation. Diagnosis is usually based on endoscopic and pathologic evidence showing malignant cells limited to the epithelium, without invasion beyond the basement membrane.
When to use this code
Use D00.1 when the provider documents carcinoma in situ of the esophagus, esophageal intraepithelial neoplasia, or a similar noninvasive malignant lesion. It is appropriate when pathology confirms an in situ process and no invasive cancer is stated. Check documentation if the report is ambiguous or only says dysplasia.
Do not use for
Do not assign this code for invasive esophageal cancer, benign esophageal lesions, or nonspecific dysplasia without a documented in situ diagnosis. If the pathology wording does not clearly support carcinoma in situ, check documentation.
Coding tip
Code the exact site and behavior as documented; if the pathology report is unclear, query for whether the lesion is in situ or invasive.