Specific code 2014 ICD-9-CM Diagnosis Code 164.0
Malignant neoplasm of thymus
  • Billable Code
  • Short description: Malignant neopl thymus.
  • ICD-9-CM 164.0 will be replaced by an equivalent ICD-10-CM code (or codes) when the United States transitions from ICD-9-CM to ICD-10-CM on October 1, 2015.
  • ICD-9-CM 164.0 is a billable medical code that can be used to specify a diagnosis on a reimbursement claim.
Disease Synonyms
  • Cancer of the thymus
  • Cancer of the thymus, small cell
  • Cancer of the thymus, squamous cell
  • Cancer of the thymus, thymoma
  • Malignant thymoma
  • Primary malignant neoplasm of thymus
  • Primary small cell neoplasm of thymus
  • Primary squamous cell carcinoma of thymus
  • Small cell carcinoma, thymus
  • Squamous cell carcinoma, thymus
  • Thymus cancer
Clinical Information
  • Primary or metastatic malignant neoplasm involving the thymus. This category includes malignant thymomas, thymic lymphomas, primary thymic carcinomas, and metastatic carcinomas from other anatomic sites.
164.0 Excludes
  • benign carcinoid tumor of the thymus (209.62)
  • malignant carcinoid tumor of the thymus (209.22)
Convert to ICD-10-CM: 164.0 converts directly to:
  • 2014 ICD-10-CM C37 Malignant neoplasm of thymus
ICD-9-CM Volume 2 Index entries containing back-references to 164.0:
  • Carcinoma (M8010/3) - see also Neoplasm, by site, malignant
    • thymic (M8580/3) 164.0
  • Thymoma (benign) (M8580/0) 212.6
    • malignant (M8580/3) 164.0
ICD-9-CM codes are used in medical billing and coding to describe diseases, injuries, symptoms and conditions. ICD-9-CM 164.0 is one of thousands of ICD-9-CM codes used in healthcare. Although ICD-9-CM and CPT codes are largely numeric, they differ in that CPT codes describe medical procedures and services. Can't find a code? Start at the root of ICD-9-CM, check the 2014 ICD-9-CM Index or use the search engine at the top of this page to lookup any code.