Lymphocytic adenohypophysitis: clinical, radiological, and magnetic resonance imaging characterization.

Lymphocytic adenohypophysitis is a rare nonneoplastic cause of a pituitary mass. We report the case of an 18-year-old woman who presented with complaints of headaches and visual disturbances after an otherwise uncomplicated pregnancy and delivery. She had an elevated serum prolactin level and a pituitary mass visualized by magnetic resonance imaging (MRI). The tissue removed by transsphenoidal resection was an inflammatory mass composed of lymphocytes, plasma cells, and moderate fibrosis surrounding islands of hyperplastic lactotrophs. This is the first case of lymphocytic adenohypophysitis visualized by MRI. As in this case, lymphocytic adenohypophysitis is frequently confused with a prolactin-secreting pituitary tumor before operation and pathological examination of the tissue. The clinical characteristics and radiological features of and an approach to managing patients with lymphocytic adenohypophysitis are reviewed and discussed.