Carcinoma in situ of skin of lip

This code represents a non-invasive, pre-malignant lesion where abnormal epithelial cells are confined to the epidermis of the lip, without evidence of invasion into the dermis. It signifies the earliest stage of squamous cell carcinoma, often referred to as Bowen's disease or intraepidermal carcinoma of the lip.

Use this code when documentation specifies "carcinoma in situ" or "intraepidermal carcinoma" of the lip, typically confirmed by biopsy. This applies to lesions that have not breached the basement membrane, indicating a localized, superficial malignancy.

• Differentiate carefully from invasive squamous cell carcinoma of the lip, which would be coded under malignant neoplasm categories.
• Ensure the pathology report explicitly states "in situ" or "intraepidermal" and specifies the lip as the anatomical site.
• Do not use for dysplastic nevi or other benign or pre-malignant conditions that are not explicitly carcinoma in situ.