Primary sarcomas of the pulmonary vein are extremely rare. Although myxomas are the most common intracavitary tumor of the left atrium, some findings should alert the clinician to the probability of malignancy. A 28-year-old woman developed hemoptysis, night fever, generalized malaise, anorexia and weight loss for 2 months, with progressive dyspnea for 2 weeks. She was preoperatively diagnosed as left atrial myxoma with a concurrent right lower lung tumor.