ICD-10 Code C43.112 – Malignant melanoma of right lower eyelid, including canthus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C43.112 – Malignant melanoma of right lower eyelid, including canthus
What it is
C43.112 identifies a malignant melanoma located on the right lower eyelid, including the canthus. Use it when documentation specifies this exact anatomic site and a melanoma diagnosis.
Clinical signs
Clinical features may include a pigmented or changing eyelid lesion, irregular borders, or abnormal growth. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents malignant melanoma on the right lower eyelid or right canthus. It also applies when pathology confirms melanoma at this site and the record clearly identifies the right side.
If laterality or exact eyelid location is unclear, check documentation before coding. Do not infer the site from a general facial skin cancer note.
Do not use for
Do not use this code for benign eyelid lesions, nonmelanoma skin cancers, or melanoma of the left eyelid. Check documentation if the lesion is on the upper eyelid or another facial site.
Coding tip
Verify both laterality and eyelid location, because canthus involvement is included in this code.