GH1 and Microprolactinoma: In another report of 112 (30 GH-secreting, 25 PRL-secreting, 15 ACTH-secreting, and 42 nonfunctioning tumors) and 13 normal anterior pituitary gland specimens, ACTH-secreting adenomas were, like microprolactinomas, had much lower vascular density than the normal pituitary tissue and other secreting and nonsecreting tumor types [7].