#1: Primary site
Source 1: 2018 SEER Manual
Notes: Appendix C: Breast Coding Guidelines
Primary site--Breast: how is subsite coded for a breast cancer when it is described as central portion between 1-3:00 or central portion at 12:00?
See the SEER coding guidelines for breast, https://seer.cancer.gov/manuals/2018/AppendixC/Coding_Guidelines_Breast_2018.pdf Generally, codes C502 - C505 are preferred over C501. C501 would be preferred over C508. Apply these general guidelines when there is no other way to determine the subsite using the available medical documentation.
Table 1, Primary Site codes, in the breast solid tumor rules also provide helpful information for coding site.