We describe a case of lymphocytic panhypophysitis (LPH) in a 30-year-old woman presenting with throbbing headaches and vision changes during her third trimester. LPH is the rarest subclassification of lymphocytic hypophysitis; it is typically found in males and has not previously been associated with pregnancy. Anterior and posterior pituitary deficits together with headaches should raise a high degree of suspicion regarding the possibility of LPH. The atypical magnetic resonance imaging finding of a heterogeneous pituitary mass additionally raised concern about pituitary apoplexy. Tissue from a transsphenoidal biopsy permitted diagnosis of lymphocytic hypophysitis. There was infiltration of the pituitary gland by small B and T lymphocytes. Resolution of the visual symptoms occurred after the biopsy and treatment with intravenous steroids.