We report on the rare finding of pituitary tissue, including both adenohypo
physis and neurohypophsis, in a mature cystic teratoma of the ovary removed
from a 26 year old female at the time of cesarean section. Immunocytochemi
stry of the ectopic anterior pituitary component showed pregnancy-related c
hanges that have previously only been described in pituitaries obtained at
autopsy.