ICD-10 Code D03.12 – Melanoma in situ of left eyelid, including canthus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D03.12 – Melanoma in situ of left eyelid, including canthus
What it is
This code identifies melanoma in situ limited to the left eyelid, including the canthus. The lesion is confined to the epidermis and has not invaded deeper tissue.
Clinical signs
Findings may include a pigmented or variably colored lesion on the left eyelid margin or canthus, with asymmetry, border irregularity, or color variation. Clinical features vary; refer to documentation.
When to use this code
Use D03.12 when the provider documents melanoma in situ of the left eyelid, including the inner or outer canthus. Code it when pathology or clinical assessment confirms in situ disease and laterality is specified. If the note does not clearly state left-sided eyelid involvement, check documentation.
Do not use for
Do not use this code for invasive melanoma, uncertain behavior lesions, or nonmelanoma skin cancers. It also should not be used when the site is the right eyelid or laterality is not documented.
Coding tip
Confirm both “in situ” and “left eyelid, including canthus” in the record before assigning D03.12.