Lymphocytic hypophysitis: Report of an unusual case of a rare disorder

A 36-year-old non-pregnant woman presented with a four-month history of pro gressive visual deterioration and amenorrhea. The latest gestation was 6 ye ars earlier. Hormonal study revealed central diabetes insipidus, hypopituit arism, and slightly increased prolactin level. Ophthalmologic examination s howed bilateral hemianopsia. In the magnetic resonance imaging an intrasell ar mass with supra and retrosellar extension was found. The mass showed a p olylobular aspect with heterogeneous signal within the tissue. The normal n eurohypophysis could not be identified. Pterional craniotomy was performed. The pathological examinations revealed fibrous tissue with heavy inflammat ory infiltrate composed of lymphocytes and plasma cells, islands of eosinop hilic epithelial cells stained positively for chromogranin, GH, ACTH, and P RL and negatively for antibodies directed against HLA-II antigens. This cas e of lymphocytic hypophysitis was not related to pregnancy and involved the neurohypophysis. We discuss the features that can help to make a preoperat ive differential diagnosis.