V.1.2 Identification of Separate Sites

For Cases Diagnosed January 1, 2005 through December 31, 2006

For cases diagnosed January 1, 2005 through December 31, 2006, apply the SEER Multiple Primary and Histology Rules as written in the SEER Program Coding and Staging Manual, 2004.

For Cases Diagnosed Prior to January 1, 2005

A principal way of determining how many primary tumors a patient has is the identification of separate sites. For further discussion of primaries, see Section II.1.2 and Section II.1.3).

For colon, rectum, anus, and anal canal, bone, peripheral nerves and autonomic nervous system, connective tissue, and melanoma of skin, each subcategory (4 characters) as delineated in ICD-O-3, is considered to be a separate site.

The site groups shown in Appendix N are each to be considered one site when determining multiples.

For all other sites, each category (3-characters) as delineated in ICD-O-3, is considered to be a separate site.

With cases diagnosed prior to January 1, 2007, if tumors of the same histology occur in more than one subsite within two months of each other, record them as a single primary and code the 9 topographic subcategory. For paired organs, see Section II.1.3.3.

Examples:

Independent tumors occurring in the transverse colon (C18.4) and descending colon (C18.6) must be reported separately as different primaries, whatever their histologic types and whether or not they appear within two months of each other.

Base of tongue (C01.9) and border of tongue (C02.1) are considered subsites of the tongue and would be treated as one site-either overlapping lesion of parts of the tongue (C02.8) or tongue, NOS (C02.9).

Report tumors of the same histology appearing in the trigone of the urinary bladder (C67.0) and the lateral wall of the urinary bladder (C67.2) as a single primary and enter code C679.