Carcinoma in situ of pharynx

This code signifies the presence of abnormal, non-invasive epithelial cells confined to the pharyngeal mucosa, indicating a pre-malignant condition without evidence of invasion into deeper tissues. It represents the earliest stage of cancer development within the pharynx.

Apply this code when pathology reports confirm carcinoma in situ of any part of the pharynx, including the nasopharynx, oropharynx, or hypopharynx. Documentation must explicitly state "carcinoma in situ" or "CIS" and specify the pharynx as the anatomical site.

• Ensure the pathology report clearly distinguishes "in situ" from invasive carcinoma.
• Do not use this code for dysplasia or atypical hyperplasia; these are coded differently.
• Sequence this code as the primary diagnosis when it is the reason for the encounter, such as for surgical excision or surveillance.