[Pulmonary tumor embolism caused by asymptomatic gastric cancer]

A 42-year-old man was hospitalized for evaluation of hypoxemia. Laboratory findings were consistent with diffuse intravascular coagulation, and the level of carcinoembryonic antigen in serum was high. Despite intensive treatment, the patient died due to hypoxemia 20 hours after admission. An autopsy revealed gastric cancer in the antrum with metastases due to the lymph nodes, liver, and bone marrow. No metastases were found in the lung parenchyma but the pulmonary microvasculature was occluded by tumor-cell microemboli. Pulmonary tumor embolism must be suspected in patients who present with hypoxemia but without parenchymal opacities on chest roentgenograms, even if there are no history of malignancy.