2006 ICD-9-CM Volume 1 Diagnosis Codes Home > Neoplasms 140-239 > Malignant Neoplasm Of Respiratory And Intrathoracic Organs 160-165 > 2006 ICD-9-CM Diagnosis 164 Malignant neoplasm of thymus heart and mediastinum View the most recent version of ICD-9-CM 164 164 is a non-specific code that cannot be used to specify a diagnosis