Ca in situ skin of right lower eyelid, including canthus

This code signifies the presence of non-invasive malignant cells confined to the epidermis of the skin on the right lower eyelid, including the inner or outer corner of the eye. It represents an early stage of cancer that has not yet spread beyond the top layer of skin.

Use this code when documentation clearly indicates a diagnosis of carcinoma in situ affecting the skin of the right lower eyelid, specifically mentioning involvement of the canthus. This diagnosis is typically confirmed by biopsy results showing intraepidermal neoplastic cells without invasion of the dermis.

• Differentiate from invasive squamous cell carcinoma or basal cell carcinoma; this code is strictly for in situ lesions.
• Ensure laterality is explicitly documented as "right" and the specific anatomical site "lower eyelid, including canthus" is confirmed.
• Do not use for melanoma in situ; a different code series (D03.-) is appropriate for those diagnoses.