California Cancer Reporting System Standards Volume I: Abstracting and Coding Procedures for Hospitals
Metastasis is the dissemination of tumor cells from the primary site to a remote part of the body. It is important to distinguish metastatic lesions from new primaries. A metastatic lesion is not a primary tumor. Pathologic reports are usually the best source. The term "secondary" is sometimes used for a metastatic lesion. Since the lymphatic system is one of the main routes of metastasis, frequent reference will be found in examinations of the lymph nodes. Occurrence of a lesion in a lymph node ordinarily indicates metastasis.