Clinically unsuspected pulmonary embolism--an important secondary finding in oncology CT.

AIM: To determine the rate of finding incidental pulmonary embolisms (PE) at staging or follow-up chest computed tomography (CT) in oncology patients.

MATERIALS AND METHODS: Three hundred and eighty-five consecutive chest CT examinations, performed in patients with cancer, were prospectively assessed during a 9-month period between October 2003 and June 2004. These were spiral acquisitions between 5 and 8mm collimation acquired 25s after intravenous contrast medium administration. PE was diagnosed if a filling defect was seen in the central pulmonary arteries on two or more consecutive slices.

RESULTS: Ten of 385 (2.6%) of these patients had incidentally detected PE. This was not attributable to any specific malignancy or chemotherapeutic regimen. These emboli were all central, between the main pulmonary artery and the lobar level. Although the significance of these findings in patients not clinically suspected of having PE could be contentious, all the patients were started on therapeutic anticoagulation as a result of this observation.

CONCLUSION: Over one in 40 oncology patients have incidental central PE visible on the CT images performed to assess their malignancy. Formal review of the pulmonary arteries, using a work station, is advised in patients with malignancy.