Possibility of My Greek being mixed from that area with something else. (Italian, test)

[Westerntraveler]

Hello everybody, I took 23andme.....It told me I was 64 percent Northern European,4.5 percent East European, 30 percent undefined European among other things.....Many surprising nationalities came up and one of them was Greek. I was wondering if I could have anything else from that area like Spaniard or Italian since they are from the same part of Europe and that DNA test only goes back to 500 years..
Thanks in advance