ICD-10 Code C69.80 – Malignant neoplasm of overlapping sites of unspecified eye and adnexa (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C69.80 – Malignant neoplasm of overlapping sites of unspecified eye and adnexa
What it is
This code identifies a malignant tumor involving overlapping sites of the eye and adnexa when the exact subsite is not specified. Use it when documentation confirms cancer but does not name a more precise location.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include a documented ocular or periocular mass, vision changes, pain, irritation, or abnormal examination results supporting malignancy.
When to use this code
Use C69.80 when the record states malignant neoplasm of overlapping sites in the eye or adnexa and no single site can be assigned. It also fits when the provider documents a cancer spanning adjacent structures. If the note names a specific eye structure, code that site instead.
Do not use for
Do not use this code for benign, in situ, or uncertain neoplasms. Also avoid it when documentation identifies a more specific eye or adnexal primary site.
Coding tip
Check the operative note, pathology, and assessment for the exact anatomic site before defaulting to an overlapping-site code.