A mass that arises from the pituitary gland is called a pituitary adenoma. It is usually benign. It is classified based on the size of the mass and the type of cells that predominate in the tumor. These tumors can be functioning or nonfunctioning. Their function is based on the type of cells that comprise them. Tumors that are less than 10 mm in size are called pituitary microadenoma while those that are more than 10 mm are called pituitary macroadenoma. A pituitary microadenoma does not usually cause symptoms because they are small and they do not impinge on the » » » [Read more]