ICD-10 Code D04.2 – Carcinoma in situ of skin of ear and external auricular canal (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D04.2 – Carcinoma in situ of skin of ear and external auricular canal
What it is
D04.2 identifies carcinoma in situ, a noninvasive malignant lesion confined to the skin of the ear or external auricular canal. The abnormal cells have not penetrated deeper tissue.
Clinical signs
Clinical features vary; refer to documentation. Typical findings include a localized suspicious skin lesion on the ear or ear canal, often with biopsy confirmation of in situ disease.
When to use this code
Use D04.2 when the provider documents carcinoma in situ limited to the skin of the ear or external auricular canal. Code it after pathology or other clinical documentation confirms a noninvasive lesion in that site. If the record only says “skin cancer” or gives an uncertain site, check documentation.
Do not use for
Do not use this code for invasive skin cancer, benign lesions, or carcinoma in situ at another skin site. If the diagnosis is not clearly limited to the ear or external auricular canal, verify the record.
Coding tip
Match the code to both the exact anatomic site and the in situ wording in the chart.