The lymphocytic hypophysitis, appearing in women during the third trimester of
pregnancy or early post-partum period, is a rare cause of hypopituitarism and pituitary
enlargement. A 39 year-old woman presented in the 37th week of pregnancy with bilateral
heteronymous quadrantanopsia, CT indicative of tumorous mass and symptoms of
hypopituitarism with decreased thyroid hormone and thyrotrophin levels, and low normal
level of cortisol. After the birth of a healthy male child the patient breastfed for 10
days, sight disturbances disappeared, but amenorrhea persisted. Upon admittance the
visual field showed no abnormalities. MR of the sellar region confirmed previous CT
findings. Endocrinological testing confirmed secondary hypothyroidism and cortisol
deficiency, normal levels of prolactin with satisfactory reaction to thyroliberin. Histology
showed mononuclear infiltration, and immunohistochemistry revealed T-cells (CD3)
at the borders, and B-cells (CD20) in the follicular center. Due to enlargement of the pituitary
associated with hypopituitarism, an incorrect diagnosis of a tumor could be mad
