shroom
Yep. That is where a cluster of granulocytes secreted their payload. They have chemicals and enzymes designed to destroy foreign invaders, such as parasites. They will cause small superficial lesions on the tongue. It is known as geographic tongue.
Now, I should also mention that B 12 deficiency can cause similar phenomenon. But, if the rest of the tongue is white, I would gamble on the first explanation.
Shroom