Carcinoma in situ of skin of trunk, except scrotum

This code signifies the presence of non-invasive malignant cells confined to the epidermis (the outermost layer of the skin) on the trunk, excluding the scrotum. This condition, often referred to as Bowen's disease, represents an early stage of squamous cell carcinoma where the cancerous cells have not yet invaded deeper tissues.

Use this code when documentation specifies carcinoma in situ of the skin on the patient's trunk (e.g., back, chest, abdomen, flanks) and explicitly excludes the scrotum. This diagnosis is typically made following a biopsy confirming intraepidermal squamous cell carcinoma without dermal invasion.

• Ensure the documentation clearly states "in situ" and specifies a trunk location, excluding the scrotum.
• Differentiate from invasive squamous cell carcinoma of the skin, which would be coded to a different category.
• Do not use for melanoma in situ, which has its own specific codes.