I would guess somewhere around 12 points, given that the sandwich came from a deli where bread slices tend to be larger and fillings tend to be high fat.
2 slices deli bread - 6 pts
1/2 c. tuna salad - 6 pts
Dill pickle - 0 pts
Diet Iced Tea - I'm assuming this is 0 pts?
Hope this helps. These things are very hard to estimate without any idea as to how large the portion size was.
Thank you for your post - I had figured 9 pts., but that was assuming the bread was 2 pts. You are probably right - I'll go with the 12 just to be safe (and will make my OWN tuna sandwiches from now on!!)