Carcinoma in situ of larynx

This code represents a non-invasive malignant neoplasm confined to the epithelial layer of the larynx, without evidence of stromal invasion. It signifies the earliest stage of laryngeal cancer, where abnormal cells are present but have not spread beyond the original tissue.

Use this code when pathology reports confirm carcinoma in situ of any laryngeal subsite (e.g., glottis, supraglottis, subglottis). Documentation should explicitly state "carcinoma in situ" or "CIS" of the larynx, often following a biopsy or laryngoscopy.

• Differentiate carefully from invasive laryngeal carcinoma (e.g., 161.x series) based on pathology findings.
• Ensure the documentation specifies the larynx as the primary site; do not use for other head and neck sites.
• This code is for the primary diagnosis; do not use for secondary or metastatic sites.