GH1 and prolactin-producing pituitary gland adenoma: The incidence of malignancy was studied in patients with chronic excess of growth hormone (acromegaly) in particular, while this topic has been rarely studied in patients with non-functioning pituitary adenoma and prolactinomas (Popovic et al. 1998, Erfurth et al. 2001, Minniti et al. 2005, Norberg et al. 2008, Sattler et al. 2012, Child et al. 2015, Boguszewski & Ayuk 2016, Olsson et al. 2017, Terzolo et al. 2017, Battistone et al. 2021).