FIGURE 2. MRI scans with coronal ( A,C ) and sagittal ( B,D ) views demonstrating a prolactin-secreting macroadenoma before pregnancy ( A,B ) that progressively enlarged during pregnancy. The third trimester is shown here ( C,D ). The patient had been complaining of increasing headaches. ( From Molitch ME. Medical treatment of prolactinomas. Endocrinol Metab Clin North Am 1999;28:143-170 )