Etiologic diagnosis of hepatic lesions in cancer patients. Value of ultrasound and liver function tests.

The purpose of this study was to evaluate the value of a combination of ultrasound (US) and liver function tests (LFT) for determination of the benign or malignant nature of one or more hepatic lesions in cancer patients. A total of 1235 patients with hepatic metastases and 832 patients with benign liver lesions investigated by US-LFT over a 12-year period were analyzed retrospectively. Ultrasound patterns considered indicative of a benign process (cyst, calcification without mass, irregular hyperechoic area without mass effect, small hyperechoic focal lesion as less than 3 cm) or malignancy (peritumoral halo, hypoechoic focal lesion, multiple solid nodules) were associated with LFT results. A US pattern of a benign process associated with normal LFT led to a diagnosis of benign disease with a false negative rate for malignancy of 11.6%. The highest figure corresponded to small hyperechoic nodules, for which the positive predictive value of malignancy (PPVM) depended on the type of primary cancer: 2.1% for breast cancer versus 62.5% for colorectal cancer. A US criterion of malignancy associated with abnormal LFT led to a diagnosis of malignancy (PPV 96.2% to 100%). Overall, the combination of US and LFT had a sensitivity of 80.6% and a specificity of 99.4%. The US-LFT combination correctly determined the benign or malignant nature of 74.5% of all hepatic lesions; the PPV was never less than 96.2% (small and solitary hyperechoic focal lesions were excluded because their PPV for malignancy is too high).