LYMPHOCYTIC HYPOPHYSITIS SIMULATING A PITUITARY-ADENOMA IN A NONPREGNANT WOMAN

Lymphocytic adenohypophysitis can cause pituitary expansion and hypopi tuitarism closely mimicking the features of a pituitary adenoma. In co ntrast to pituitary adenoma, lymphocytic adenohypophysitis occurs almo st exclusively in young women in relation to pregnancy. We report a ca se of a 43-year-old nonpregnant nullipara who exhibited an intrasellar mass with diffuse homogeneous contrast enhancement on magnetic resona nce imaging scanning. Serum hormone analyses revealed secondary hypoad renalism, hypothyroidism, and hypogonadism. The patient underwent surg ery for a presumed nonsecreting pituitary adenoma. Histopathological e xamination showed extensive infiltration of the anterior pituitary gla nd by chronic inflammatory cells. The immunohistochemical pattern of t he inflammatory cells indicated the chronic and putatively autoimmune nature of the disease.