Can anyone tell me whether I should be concerned about tiny blisters (a larger one had the size of a pinhead) surrounding the location of where my tumor was? They are painless and firm, and come and go rapidly.

Two and a half months ago I underwent surgery (no additional treatment was needed) to remove a small (ca. 1cm), early stage, low grade mucoepidermoid carcinoma from my palate. The excision was approximately 4 x 3.5 cm and went in part down to the bone. The wound has healed completely, and has been hardly visible for the last month.
The regrown tissue looks like that of the rest of my palate, with the exception of where the tumor itself used to be (it is more reddish).