Tumor embolism as the first manifestation of cancer

Major tumor emboli (obstructing segmental or larger branches of the pulmonary artery) are a rare mechanism of spread of cancer to the lungs. Less frequently are tumor emboli the cause of respiratory failure and death. The present case of major tumor embolism as the initial manifestation of cancer is unusual for the chronicity, documentation of recurrence, and tissue pathology encountered. In retrospect, we can describe clues which may arouse suspicion of tumor embolism in future cases.