Carcinoma in situ of stomach

This code signifies the presence of abnormal, cancerous cells confined to the glandular or epithelial lining of the stomach, without invasion into deeper tissues. It represents a pre-invasive form of cancer, also known as intraepithelial neoplasia or non-invasive carcinoma.

Apply this code when pathology reports confirm carcinoma in situ of any part of the stomach. Documentation should explicitly state "carcinoma in situ," "intraepithelial neoplasia," or "non-invasive carcinoma" of the stomach, without evidence of stromal invasion.

• Differentiate from malignant neoplasm of the stomach (invasive cancer) which involves deeper tissue layers.
• Ensure the pathology report clearly specifies "in situ" to avoid miscoding as invasive carcinoma.
• Do not use for dysplasia or adenoma without a definitive diagnosis of carcinoma in situ.