Incidence of pharyngeal hypophysis in neonates a histologic study

The presence of adenohypophysial tissue in the nasopharynx is no longer dis puted. This study was performed in 50 neonatal cadavers subjected to medica l autopsy within 6 hours of death. The aim was to study the incidence of ex trasellar pituitary tissue in the nasopharynx and its various histologic ce ll types. The transpalatal approach was used to obtain the specimens. The s pecimens were stained with hematoxylin and eosin and periodic acid-Schiff-o range G for selective demonstration of adenohypophysial cells. Histopatholo gic evaluation led to the detection of pituitary tissue in 16% of the exami ned specimens. Selective staining demonstrated a 6% positive incidence of a denohypophysial cells. The pharyngeal hypophysis exists in 2 forms: a typic al adenohypophysial collection of cells and an atypical subepithelial clust er. The incidence of hypophysial tissue was higher in the older neonates, p erhaps because of hormonal stimulation of the caudal remnant of Rathke's po uch.