Melanoma in situ of left lower eyelid, including canthus

This code signifies a non-invasive malignant melanoma confined to the epidermis of the left lower eyelid, including the inner or outer corner (canthus). It represents the earliest stage of melanoma where the cancerous cells have not yet spread beyond the top layer of skin.

Use this code when documentation confirms a diagnosis of melanoma in situ specifically located on the left lower eyelid, encompassing the canthal region. This diagnosis is typically established through biopsy and histopathological examination.

• Ensure the documentation explicitly states "in situ" and specifies the left lower eyelid, including the canthus.
• Distinguish from invasive melanoma of the eyelid, which would be coded differently.
• Laterality (left) and specific anatomical site (lower eyelid, including canthus) are crucial for accurate code assignment.