ICD-10 Code C45

C45 is the code for mesothelioma in the World Health Organization's International Classification of Diseases, 10th Revision (ICD-10). Subcodes mark the site: C45.0 pleura, C45.1 peritoneum, C45.2 pericardium, C45.7 other sites and C45.9 unspecified. It appears on death certificates, hospital records and insurance claims.

Origin

Earlier versions of the classification had no separate code for mesothelioma, which was counted under cancers of the pleura or other sites. ICD-10, adopted by WHO in the early 1990s, introduced C45. The United States began using ICD-10 to code deaths in 1999 and adopted the clinical version, ICD-10-CM, for medical billing in 2015.

Significance in Asbestos Context

Because ICD-10 gave mesothelioma its own code, death-certificate data from 1999 onward allow more reliable counts of mesothelioma deaths, and most national statistics and research rely on it. For a family, the code on a death certificate or in medical records can matter. A death certificate that lists "lung cancer" or "cancer, unknown primary" instead of mesothelioma can raise questions in a claim, and records coded C45.9 (unspecified site) may need a pathology report to confirm where the tumor began. Testicular mesothelioma, arising from the tunica vaginalis, falls under C45.7. Related asbestos codes include J61 for asbestosis and J92.0 for pleural plaque with asbestos. Codes are administrative labels assigned by doctors or coders; a claim still depends on the underlying medical records and pathology, and an incorrect code can usually be explained or, in some cases, corrected.

Example Sentence

Her death certificate listed malignant mesothelioma of the pleura, coded C45.0, as the underlying cause of death.

Related Terms

Death Certificate, Mesothelioma, Pleural Mesothelioma, Peritoneal Mesothelioma, Pathology Report, Mesothelioma Misclassification, Cancer Registry, WHO Classification

Notes

• Check that the death certificate names mesothelioma if that was the diagnosis; ask the certifying doctor or your lawyer if it does not.
• Ask for the pathology report as well as coded records; codes alone can be wrong or incomplete.
• Medical bills and insurance statements often show diagnosis codes and can help build a timeline.