ICD-10 Code D09.22 – Carcinoma in situ of left eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D09.22 – Carcinoma in situ of left eye
What it is
Carcinoma in situ of left eye means a preinvasive malignant lesion is present in the left eye tissues. The abnormal cells are confined to the original site and have not invaded surrounding structures.
Clinical signs
Clinical features vary; refer to documentation. Diagnosis is usually based on ophthalmic examination and pathology showing in situ disease in the left eye.
When to use this code
Use this code when the provider documents carcinoma in situ affecting the left eye specifically. It applies when the lesion is confined to the site and the record identifies laterality as left. If the note only says “eye” or does not confirm in situ status, check documentation.
Do not use for
Do not use this code for invasive eye cancer, uncertain lesions, or non-neoplastic eye disorders. If the documentation does not specify the left eye, do not assume laterality.
Coding tip
Verify both the in situ diagnosis and left-eye laterality in the operative, pathology, or specialist note before assigning D09.22.