Destructive inflammatory processes of the anterior pituitary gland are unusual and are rarely recognized either during life or at autopsy. A woman with recurrent episodes of hypoglycemia was found on autopsy to have a destructive lymphoid infiltrate in her adenohypophysis that appeared to result in only partial hypopituitarism. This lesion is thought to be an autoimmune disorder and has been reproduced experimentally. Four other cases previously reported in the world literature are reviewed.