2006 ICD-9-CM Volume 1 Diagnosis Codes Home > Neoplasms 140-239 > Malignant Neoplasm Of Respiratory And Intrathoracic Organs 160-165 > ICD-9-CM Diagnosis 164 Malignant neoplasm of thymus heart and mediastinum 164 is a non-specific code that cannot be used to specify a diagnosis ICD-9-CM Diagnosis 164.0 Malignant neoplasm of thymus 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. --2003 164.0 is a specific code that can be used to specify a diagnosis 164.0 contains 2 index entries ICD-9-CM Diagnosis 164.1 Malignant neoplasm of heart Malignant neoplasms originating in the heart 164.1 is a specific code that can be used to specify a diagnosis ICD-9-CM Diagnosis 164.2 Malignant neoplasm of anterior mediastinum 164.2 is a specific code that can be used to specify a diagnosis ICD-9-CM Diagnosis 164.3 Malignant neoplasm of posterior mediastinum 164.3 is a specific code that can be used to specify a diagnosis ICD-9-CM Diagnosis 164.8 Malignant neoplasm of other parts of mediastinum 164.8 is a specific code that can be used to specify a diagnosis ICD-9-CM Diagnosis 164.9 Malignant neoplasm of mediastinum part unspecified 164.9 is a specific code that can be used to specify a diagnosis