ICD-10 Code D04.6 – Carcinoma in situ of skin of upper limb, including shoulder (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D04.6 – Carcinoma in situ of skin of upper limb, including shoulder
What it is
D04.6 identifies carcinoma in situ confined to the skin of the upper limb, including the shoulder. The lesion is noninvasive, meaning abnormal cells are present but have not spread beyond the epidermis.
Clinical signs
Findings usually include a suspicious skin lesion on the arm or shoulder, often described as a persistent plaque, scale, crust, or nonhealing area. Clinical features vary; refer to documentation and pathology when available.
When to use this code
Use D04.6 when the provider documents carcinoma in situ or an equivalent pathologic diagnosis for skin on the upper limb or shoulder. It is appropriate after biopsy or excision confirms a noninvasive malignant lesion in that location.
If the note only says “skin lesion,” “mass,” or “suspicious lesion” without a confirmed in situ diagnosis, do not assign this code. Check documentation for the exact site and whether the lesion is invasive or in situ.
Do not use for
Do not use D04.6 for benign skin growths, actinic keratosis, or invasive skin cancer. If the site is elsewhere on the body, choose the code that matches the documented anatomic location.
Coding tip
Verify both the pathology wording and the precise site before coding, because D04.6 depends on confirmed in situ disease of the upper limb or shoulder.