Figure 1. (a) The normal pituitary gland is a bean-shaped structure that hangs from the pituitary stalk (arrow), an extension of the hypothalamus that traverses the diaphragm of the sella turcica. (b) A horizontal section of the gland identifies the anterior lobe (A) or “adenohypophysis”, the posterior lobe (P) or “neurohypophysis” and the vestigial intermediate lobe (I) that is poorly developed in humans. This gland demonstrates “basophil invasion” of the posterior lobe, proliferation of corticotrophs into the neurohypophysis (arrows) that is a normal feature in older patients.