Case 1 of patient with primary mediastinal B-cell lymphoma presenting at 31weeks gestation. (A) Coronal section chest CT scan with contrast at diagnosis, pretreatment. Illustrates significant compression of SVC by tumor mass (within broken lines) on right and demonstrating extent of mass also on left superior to pulmonary artery (PA). (B) Transverse section chest CT scan with contrast at diagnosis, pretreatment. Illustrates extent of anterior mediastinal tumor mass. CT imaging suggested possible moderate-sized pericardial effusion found on echocardiography to be a small effusion. (C) Coronal section chest CT scan with contrast at completion of treatment. Normal caliber SVC with a peripherally inserted central catheter (PICC) line in situ. Small volume of residual tumor (within broken lines). Subsequent PET-CT scan demonstrated no activity confirming a complete metabolic response.