[Pulmonary tumor embolism: relationship between clinical manifestations and pathologic findings]

To elucidate the relationship between the clinical manifestations and pathologic findings in pulmonary tumor embolism, we reviewed the autopsy and clinical records of 318 patients who died of various cancers, excluding lung cancer. Sixty-seven (21%) of the patients had at least one tumor embolus in the pulmonary arteries and 12 (3.8%) had multiple tumor emboli contributing to death. We considered that the 12 patients (6 with hepatoma, 3 with gastric cancer, and one each with colon cancer, pelvic cancer, and cervical cancer) had disease defined as pulmonary tumor embolism, and we fully analyzed these cases. Patients with hepatoma had manifestations of submassive pulmonary thromboembolism and patients with other cancers had manifestations of pulmonary microthromboembolism. The lungs of all of the 6 patients with hepatoma had both microscopic and macroscopic tumor emboli and 3 cases were accompanied by pulmonary infarction. On the other hand, the lungs of all of the remaining 6 patients had microscopic (including intracapillary) tumor emboli and 4 cases were accompanied by diffuse alveolar damage. The lung of 1 of the patients with hepatoma and 2 of the patients with other cancers also had pulmonary tumor thrombotic microangiopathy. In patients with hepatoma, the tumor emboli seemed to be derived from tumor invasion to large veins, while the tumor emboli seemed to be derived from widespread tumor invasion to lymphatic channels in the remaining patients. The authors conclude that pulmonary tumor embolism shows heterogeneous manifestations such as acute and subacute cor pulmonale and diffuse alveolar damage. Clinicians should keep in mind that the heterogeneity of the disease is closely associated with the varieties of malignancies and their spread.