Thrombosis of the inferior vena cava and malignant disease.

BACKGROUND: Inferior vena cava thrombosis (IVCT) is a rare event, and studies detailing its underlying aetiologies are scarce.

METHODS: One hundred and forty-one IVCT patients (57% females, median age 47 years) were analysed with a focus on malignancy-related thrombosis and compared with 141 age- and sex-matched control patients with isolated lower-extremity deep vein thrombosis.

RESULTS: Malignancies were more prevalent among IVCT patients compared with the control group (39% vs. 7.8%; P<0.001). Malignancy-related IVCT more frequently involved the suprarenal and hepatic segments of the IVC and extended more often to the right atrium than IVCT did in non-cancer patients. Among IVCT patients with malignancies, renal cell carcinoma (38%) and other malignancies of the genitourinary tract (25%) were the most common tumours. Analysis of the underlying pathological mechanisms of malignancy-related thrombosis identified external compression of the IVC by tumour masses in 9 cases (16%), and progression of malignancy into the IVC (so-called "tumour thrombosis") in 24 cases (44%). The remaining 22 cases (40%) were attributed to malignancy-related hypercoagulability and the presence of additional venous thromboembolism risk factors, such as previous surgery, immobilisation, or chemotherapy.

CONCLUSIONS: Malignancies substantially contribute to the risk of thrombosis involving the IVC. Tumour invasion, especially in cases of renal cell cancer and malignancy-related hypercoagulability are major triggering factors for thrombogenesis.