PRL and craniopharyngioma: However, young people's necropsy studiesalso show a high prevalence of pituitary microadenomas, which most frequently immuno-stain for prolactin [11].Twelve of the 24 patients with craniopharyngiomas who were older than 40 years old who were described by Russell and Pennybacker[15] had memory impairment, and eight had dementia.