Carcinoma in situ of other specified sites of skin

This code represents the presence of abnormal, malignant cells that are confined to the epidermis (the outermost layer of the skin) and have not invaded deeper tissues. It signifies a pre-invasive form of skin cancer, often referred to as Bowen's disease or squamous cell carcinoma in situ. The "other specified sites" indicates locations other than those explicitly categorized elsewhere, such as lip, eyelid, ear, or genital organs.

Use this code when documentation clearly states "carcinoma in situ" or "Bowen's disease" of a skin site not otherwise specified. This diagnosis is typically confirmed by biopsy showing full-thickness epidermal atypia without dermal invasion. It is appropriate for initial diagnosis and subsequent encounters related to this specific condition.

• Ensure the documentation specifies "in situ" to differentiate from invasive carcinoma.
• Verify the anatomical site; if a more specific ICD-9-CM code exists for that site (e.g., lip, eyelid), use that instead.
• Do not use this code for melanoma in situ; a separate code exists for that condition.