The Differential Diagnosis of Pituitary Stalk Thickening

The pituitary stalk (also called the infundibulum) is a funnel-shaped structure that passes through the dura mater of the diaphragma sellae and connects the hypothalamus to the pituitary gland. It is divided into the anterior pars tuberalis and posterior pars infundibularis. The pars tuberalis is part of the anterior pituitary and contains a few gonadotroph and corticotroph cells. The pars infundibularis (infundibular stem) contains the unmyelinated axons of the magnocellular supraoptic and paraventricular neurons that end in the posterior pituitary, where they release oxytocin and vasopressin into the bloodstream ( 1. Larkin S. Ansorge O. et al. Development and microscopic anatomy of the pituitary gland. in: Feingold K.R. Anawalt B. Boyce A. Endotext [Internet]. MDText.com, Inc, South Dartmouth, MA2000–2017 Google Scholar ). On the posterior portion of the stalk are tortuous capillary loops surrounding a central capillary, termed gomitoli, that are part of the complex hypothalamo-hypophyseal portal system.