![](https://www.endotext.org/wp-content/uploads/2018/10/etx-pit-new-ch26-fig1.png)
Figure 1. Factors involved in pathogenesis of primary empty sella including the upper-sellar factors, incompetence or incomplete formation of the sellar diaphragm, and pituitary factors associated with the variation in the pituitary volume. Modified from Bioscientifica Ltd., Chiloiro S et al, European Journal of Endocrinology (2017) 177, R275–R285