A 39-year-old male without any significant complaints or symptoms presented with a calcified lesion located at the sellar region.Total removal of the lesion has been achieved via an endoscopic endonasal transsphenoidal approach. Histopathological examination of the lesion revealed a pituitary stone. This report describes the first pituitary stone formed within a plurihormonal pituitary adenoma and also differs from previous studies in means of chosen surgical method that is the first endoscopic approach to a pituitary stone. Additionally, by reviewing previous cases, a classification has been proposed and possible pathophysiological mechanisms behind this rare entity have been discussed.