ICD-10 Code D05.80 – Other specified type of carcinoma in situ of unspecified breast (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D05.80 – Other specified type of carcinoma in situ of unspecified breast
What it is
This code identifies carcinoma in situ of the breast when the lesion is confined to the ducts or lobules and the record does not specify a more exact breast site. Use it for an in situ breast cancer described as other specified type.
Clinical signs
Findings may include an abnormal breast imaging result, a biopsy showing in situ malignancy, or pathology describing ductal or lobular carcinoma in situ. Clinical features vary; refer to documentation.
When to use this code
Use D05.80 when the provider documents carcinoma in situ of the breast but does not identify a more specific breast location or subtype. It also fits when the record says “other specified type” and no further detail is available. Check documentation if laterality or a more precise code is stated elsewhere.
Do not use for
Do not use this code for invasive breast cancer or for benign breast lesions. If the documentation identifies a different in situ breast site or a more specific diagnosis, code that instead.
Coding tip
Confirm the pathology wording carefully; unspecified breast site and “other specified type” must both be supported by the record.