Abstract
Summary Giant prolactinomas are a rare entity; during pregnancy, the risk for complications associated with these tumors is higher. Here, we report a case of a young woman who had an invasive, giant prolactinoma post resection with residual disease who became pregnant. This patient was treated with cabergoline to prevent tumor expansion in pregnancy, resulting in the uneventful delivery of a healthy baby boy. Learning points: Giant prolactinoma can cause both diagnostic and therapeutic challenges given their atypical presentation. Accurate diagnosis is paramount to avoid unnecessary surgical intervention or pituitary irradiation. This case demonstrates the effectiveness and safety of CAB therapy during pregnancy.