Lymphoid adenohypophysitis.

A rare case of lymphoid adenohypophysitis in a 28-year-old woman with temporal relation to pregnancy is described. A CT scan disclosed a round, contrast-enhancing sellar mass simulating pituitary adenoma, and endocrine evaluation showed mild hypopituitarism. Histological examination of the specimen obtained by transsphenoidal hypophysectomy after uneventful natural labour showed marked diffuse infiltration of mature lymphocytes with many germinal centers within lymphoid follicles. This finding was the same as previously reported. The present case makes a total of 15 cases reported in the world literature up to date. To our knowledge, no report has been documented in Japan.