Simplify the following text for a Grade 12 native English-speaking person.
Original: The term prostatitis refers in its strictest sense to histological ( microscopic ) inflammation of the tissue of the prostate gland , although historically the term has loosely been used as a rubric to describe a set of quite different conditions .
Simplified: The term prostatitis refers , in its strictest sense , to histological ( microscopic ) inflammation of the tissue of the prostate gland .