ICD-10 Code C43.10 – Malignant melanoma of unspecified eyelid, including canthus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C43.10 – Malignant melanoma of unspecified eyelid, including canthus
What it is
C43.10 identifies a malignant melanoma arising on the eyelid or canthus when the exact eyelid location is not specified. Use it for a confirmed melanoma diagnosis, not for suspicious lesions or benign skin changes.
Clinical signs
Clinical features vary; refer to documentation. Melanoma may appear as a changing pigmented lesion, irregularly shaped mass, or lesion with asymmetry, border irregularity, color variation, or growth.
When to use this code
Use this code when the provider documents malignant melanoma of the eyelid or canthus but does not specify upper, lower, left, or right eyelid. It also applies when the record states the site is unspecified. Check documentation for laterality or exact eyelid location before choosing a more specific code.
Do not use for
Do not use this code for benign eyelid lesions, melanoma in situ, or uncertain masses without a confirmed malignant melanoma diagnosis. Check documentation if the note only says “suspicious,” “rule out,” or “history of melanoma.”
Coding tip
Verify pathology or provider documentation for confirmed malignancy and exact eyelid site before assigning C43.10.