Carcinoma in situ of skin of unsp eyelid, including canthus

This code signifies the presence of non-invasive malignant cells confined to the epidermis (carcinoma in situ) of an unspecified eyelid, including the canthus. It indicates that the cancerous cells have not yet invaded deeper tissues.

Use this code when documentation specifies carcinoma in situ affecting any part of an eyelid, and the laterality (right or left) is not specified. This diagnosis is typically made following a biopsy confirming the presence of squamous cell carcinoma in situ or Bowen's disease of the eyelid.

• Ensure documentation explicitly states "in situ" to differentiate from invasive carcinoma.
• If the specific eyelid (right or left) is documented, a more specific code from the D04.1 series should be used.
• Do not use this code for melanoma in situ; refer to codes in the D03 category for melanoma.