ICD-10 Code C80.0 – Disseminated malignant neoplasm, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C80.0 – Disseminated malignant neoplasm, unspecified
What it is
C80.0 identifies a malignant neoplasm that is widely spread in the body and not linked to a specific primary site in the documentation. Use it when the record describes disseminated cancer but does not name the origin.
Clinical signs
Clinical features vary; refer to documentation. Common references describe widespread metastatic disease, often with multiple involved sites or generalized cancer burden, but the primary site may remain unknown or unrecorded.
When to use this code
Use this code when the provider documents disseminated malignancy, diffuse metastatic cancer, or widespread neoplastic involvement without identifying the primary site. It may also fit when the chart states the cancer is generalized and no more specific code is supported. Check documentation if the record names a primary or metastatic site.
Do not use for
Do not use C80.0 when the primary site is known and a more specific malignant neoplasm code applies. Also avoid it for isolated secondary sites that are separately documented and codeable.
Coding tip
Code the most specific documented cancer site first; use C80.0 only when the malignancy is described as disseminated and no primary site is available.