issue of the Mayo Clinic Proceedings (pages 384 to 387). A 43-year-old woman (gravida 4, para 3) sought medical assessment during the third trimester of pregnancy because of onset of severe dyspnea. She had a 60-pack-year history of smoking but no prior medical problems. Echocardiography revealed pericardial and left pleural effusion. Thoracentesis demonstrated an exudate with cytologic findings positive for adenocarcinoma. A month before medical assessment, the patient noticed a reddish, raised coinlike lesion. A biopsy revealed metastatic adenocarcinoma. Bronchoscopy also disclosed adenocarcinoma. Computed tomography of the abdomen showed a shadow in the left hepatic lobe, consistent with metastatic involvement. At 37 weeks' gestation, the patient was delivered of a healthy female neonate. No placental lesions were found. The patient died 1 month after diagnosis. Her infant has remained healthy. Whether pregnancy alters the course of lung cancer remains unresolved. The maternal outcome of the previous patients suggests that the combination of young age, adenocarcinoma, and pregnancy is associated with aggressive tumors. The increased incidence of smoking in the female population seems to account for the increase in lung tumors.