Melanoma in situ of unspecified eyelid, including canthus

This code signifies a non-invasive malignant melanoma confined to the epidermis of an unspecified eyelid, including the inner or outer canthus. It represents the earliest stage of melanoma, where the abnormal melanocytes have not yet invaded the dermis.

Apply this code when documentation clearly states "melanoma in situ" affecting any part of the eyelid or canthus, and the specific laterality (right or left) is not specified. This diagnosis is typically confirmed by biopsy and histopathological examination.

• Ensure the pathology report explicitly states "in situ" to differentiate from invasive melanoma.
• If the laterality of the eyelid is known, use a more specific code from the D03.1- subcategory.
• Do not use this code for benign nevi or dysplastic nevi; these have different ICD-10-CM codes.