[Deep-vein thrombophlebitis and pulmonary embolism as a sign of malignant disease]

In five meticulously controlled investigations, the question of whether deep thrombophlebitis and pulmonary embolism may be signs of occult cancer was raised. One investigation was considered to be of doubtful value on account of selection. In two other investigations, an increased risk for cases of cancer was found among patients under the age of 50 years in whom suspicion of thrombophlebitis was confirmed and among patients with verified suspicion of pulmonary embolism. Two investigations reveal that the risk of cancer is particularly great if no risk factor for deep thrombophlebitis (so-called idiopathic deep thrombophlebitis) was found. In one of these investigations, problems concerning blinding were, however, present and the possible solution is not commented upon. On the present basis, arguments exist for a paraclinical investigation of patients with idiopathic deep thrombophlebitis or with pulmonary embolism. Investigation is probably only necessary in other patients with deep thrombophlebitis if symptoms suggestive of cancer are present and patients under the age of 50 years should be offered outpatient control in view of the possibility of cancer.