Hi Shuoyu,
About condiering (or not) DCIS in the computation of a TILs score, you could refer to the paper of Salgado et al. (R. Salgado et al., "The evaluation of tumor-infiltrating lymphocytes (TILs) in breast cancer: recommendations by an International TILs Working Group 2014", Ann Oncol. 2015 Feb;26(2):259-71), where they indicate that stroma surrounding DCIS should not be considered, as also pointed out by Mart in his reply.
This is a valid strategy if you want to implement a TILs score based on the recommendation of the TILs Working Group (based on the 2015 paper).
However, note that in TIGER we did not put any restrictions on the way a TILs score can be computed, so you are free to consider DCIS and other tissue compartments in your method, and also to do multiple tests with and without some morphological components, and also different parts of the tumor (the region inside, containing stroma, the invasive margin, etc.).
I hope this helps.
Regards,
Francesco