Lymphocytic adenohypophysitis: a pituitary mass lesion occurring in pregnancy. Proposal for medical treatment.

Lymphocytic adenohypophysitis is a nonneoplastic, autoimmune cause of pituitary enlargement and insufficiency. Forty-eight of the 50 reported cases have occurred in women, nearly all in association with pregnancy. Left undiagnosed and untreated, it can progress to pituitary insufficiency and death. Histologic studies show characteristic changes of autoimmune disease with lymphocytic infiltration and destruction of anterior pituitary tissue with fibrotic replacement. Lymphocytic adenohypophysitis is currently diagnosed after other pituitary mass lesions are excluded and has been treated with a combination of neurosurgery and end-organ hormone replacement. However, with improved knowledge of the pathophysiologic characteristics and natural history of the disease and with the ability to make a prospective diagnosis, we believe glucocorticoids may suppress the inflammatory response and protect remaining pituitary tissue. Two previously unreported pregnancy-associated cases are described, including one prospectively diagnosed and treated without neurosurgery during pregnancy. Obstetrician-gynecologists must place lymphocytic adenohypophysitis in the differential diagnosis of pituitary enlargement associated with pregnancy, since treatment is available and the sequelae may be life-threatening.