Ultrasound features of tumour thrombus in the IVC in retroperitoneal tumours.

Tumour invasion of the inferior vena cava (IVC) is a complication of retroperitoneal tumours that can be identified at the time of ultrasound B scanning. We have recognized nine patients with proven IVC tumour thrombus from such tumours and have noted several common ultrasound features. Six of these cases were associated with renal carcinoma, two with metastatic teratoma and one with rhabdomyosarcoma. The typical appearance included abnormal echogenic solid material in the lumen of the vessel. In sagittal section the anterior wall was domed as it stretched over the thrombus, and on real time scanning there was loss of the normal venous pulsations. Although similar abnormalities occur with non-tumour thrombus, the presence of these typical features in association with a retroperitoneal tumour is likely to represent tumour invasion of the IVC, an important observation for accurate staging and subsequent management.