Pharyngosellar pituitary: a rare developmental anomaly of the pituitary gland.

A rare malformation of the pituitary gland, termed pharyngosellar pituitary, is reported. The anterior pituitary gland was continuous from the pharyngeal roof to the sella turcica. This was found in a male fetus of gestational week 17 with an encephalocele and amnion adhesion malformation syndrome. The distribution of hormone-producing cells in the malformed pituitary tissue was irregular: thyrotropic hormone-, follicle-stimulating hormone- and luteinizing hormone-producing cells were nearly absent in the sellar and middle sections of the pituitary but were found in small numbers mainly in the pharyngeal section of the pituitary. The teratogenic determination period was estimated at between weeks 4 and 8 of gestation.