ICD-10 Code D04.22 – Carcinoma in situ of skin of left ear and external auricular canal (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D04.22 – Carcinoma in situ of skin of left ear and external auricular canal
What it is
This code identifies a noninvasive skin cancer found on the left ear or external auricular canal. The abnormal cells are confined to the top skin layer and have not crossed into deeper tissue.
Clinical signs
Clinical features vary; refer to documentation. Typical findings may include a persistent scaly, crusted, or erythematous lesion on the left ear, often noted on exam or biopsy as carcinoma in situ.
When to use this code
Use D04.22 when the provider documents carcinoma in situ limited to the skin of the left ear or external auricular canal. It also fits biopsy-confirmed in situ disease when the anatomic site is clearly specified. If the record only says “ear” without laterality or location, check documentation.
Do not use for
Do not use this code for invasive skin cancer, benign ear lesions, or lesions on the right ear. If the site is unspecified or the diagnosis is not confirmed as in situ, choose a different code.
Coding tip
Verify both laterality and the exact ear location before assigning D04.22.