Detection of occult liver metastases during EUS for staging of malignancies

Background: EUS is commonly used in the staging of GI, thoracic, and other malignancies. Studies suggest EUS can detect occult liver metastases, but the frequency with which this occurs is unknown. Methods: Records were reviewed for all patients seen during a 3-year period who underwent EUS of the upper-GI tract for staging of known or suspected malignancy. Patients were included if there was histopathologic evidence of malignancy, they had undergone noninvasive liver imaging within 6 weeks of EUS, and liver surveillance was specifically mentioned in the report of the EUS procedure. Results: A total of 222 patients were included. Liver lesions were seen in 27 patients, 17 of whom had an abnormal noninvasive liver imaging test. EUS-guided FNA of the liver was performed in 21 patients and was diagnostic of malignancy in 15 (6.8%), 5 of whom (2.3%) had normal noninvasive imaging. In 6 patients, the EUS-guided FNA result was benign. EUS missed liver lesions in 4 patients known to have abnormalities by other imaging modalities. Conclusions: EUS can detect occult liver metastases in patients in whom noninvasive hepatic imaging studies are normal, although the frequency at which such lesions are detected is low. Liver surveillance during EUS is worthwhile for patients in whom there is another indication for the procedure; but, at present, EUS should not replace traditional imaging modalities.