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Multiple Primary Neoplasms

Multiple neoplasms present many coding difficulties. These may arise in the form of:

  1. two or more separate neoplasms in different topographic sites
  2. certain conditions that are characterized by multiple tumors
  3. lymphomas, which often involve multiple lymph nodes or organs at diagnosis
  4. two or more neoplasms of different morphology arising in the same site
  5. a single neoplasm involving multiple sites whose precise origin cannot be determined

Multiple tumors are defined differently by various registries, and specific solutions to all problems cannot be given here.

For the most up-to-date information on coding rules for multiple primary neoplasms, please refer to the SEER Program site for the Multiple Primary and Histology Rules for solid tumors, and to the Hematopoietic Database and Manual for hematopoietic neoplasms.