Pituitary Histopathology in Man: Normal and Abnormal

The pituitary is a bean-shaped gland located at the base of the brain in the midline. It measures 0.6 cm SI x 0.9 cm AP x 1.3 cm and an average gland weighs 0.6 grams. Females tend to have larger glands, especially during or after pregnancy, with weights up to 1 g (1;2). The gland lies within the bony sella turcica that surrounds it inferiorly and laterally. Superiorly it is covered by the diaphragma sella, a reflection of the dura mater (3;4). Lateral to the sella are the cavernous sinuses; anteroinferior is the sphenoid sinus; anterosuperior is the optic chiasm; superior to it is the hypothalamus. The pituitary is composed of two anatomically and functionally distinct parts: the neurohypophysis and the adenohypophysis. (Figure 1)