Pharyngeal hypophysis.

Derived from embryologic remnants of Rathke's pouch and its craniopharyngeal duct, the pharyngeal hypophysis has long been considered to be present in all humans. This thesis has been recently challenged, but the weight of investigative evidence still favors the original premise. The pharyngeal hypophysis is just one product of Rathke's pouch. Others are extracranial pituitary tumors, the very rare craniopharyngioma, pharyngeal hypopharyngeal cysts, and cerebrospinal fluid rhinorrhea.