ICD-10 Code C43.21 – Malignant melanoma of right ear and external auricular canal (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C43.21 – Malignant melanoma of right ear and external auricular canal
What it is
This code identifies a malignant melanoma arising on the right ear or within the external auricular canal. Use it when documentation specifies a primary melanoma at that exact site.
Clinical signs
Clinical features vary; refer to documentation. Typical melanoma findings include a changing pigmented lesion, asymmetry, irregular borders, color variation, or ulceration on the right ear or ear canal.
When to use this code
Use C43.21 when the provider documents malignant melanoma of the right ear or external auricular canal as the diagnosis. It may appear in pathology, operative, or oncology notes. Code it only when the laterality and site are clearly stated.
Do not use for
Do not use this code for benign skin lesions, non-melanoma skin cancers, or melanoma on a different ear side. Check documentation if the site is uncertain or if the lesion is metastatic rather than primary.
Coding tip
Verify the exact anatomic site and laterality in the pathology or specialist note before assigning C43.21.