Pituitary apoplexy is attached to the hypothalamus, a part of the brain, by a stalk that also contains the blood vessels that supply the gland. It is unclear why pituitary tumors are five times more likely to bleed than other tumors in the brain. There are various proposed mechanisms by which a tumor can increase the risk of either infarction (insufficient blood supply leading to tissue dysfunction) or hemorrhage. The pituitary gland normally derives its blood supply from vessels that pass through the hypothalamus, but tumors develop a blood supply from the nearby inferior hypophyseal artery that generates a higher blood pressure,
Pituitary apoplexy or nonsecretory tumors, which do not produce excessive amounts of hormones; this might explain why the tumor has often gone undetected prior to an episode of apoplexy. The first case description of pituitary apoplexy has been attributed to the American neurologist Pearce Bailey in 1898. This was followed in 1905 by a further report from the German physician Bleibtreu. Surgery for pituitary apoplexy was described in 1925. Before the introduction of steroid replacement, the mortality from pituitary apoplexy approximated 50%. The name of the condition was coined in 1950 in a case series by physicians from Boston City Hospital and