False Positive Diagnosis of Hepatocellular Carcinoma in Liver Resection Patients.

The diagnosis of hepatocellular carcinoma (HCC) is based on imaging studies particularly in high-risk patients without histologic confirmation. This study evaluated the prevalence and characteristics of false-positively diagnosed HCC in a liver resection cohort for HCC. A retrospective review was performed of 837 liver resection cases for clinically diagnosed HCC between 2005 and 2010 at our institute. High-risk patients with tumors > 1 cm with one or two image findings consistent with HCC and tumors < 1 cm with two or more image findings consistent with HCC with persistently increased serum alpha-fetoprotein (AFP) levels above the normal range with underlying inhibited hepatitis activity underwent liver resection. The false-positive rate was 2.2% (n = 18). Of the 18 patients, 7 patients (0.8%) were diagnosed with benign conditions (one each of hemangioma, inflammation, cortical adenoma, dysplastic nodule, angiomyolipoma, bile duct adenoma, and non-neoplastic liver parenchyme) and 11 patients (1.3%) were diagnosed with malignancies (cholangiocarcinoma [n = 6], hepatoblastoma [n = 2], and one each of lymphoepithelioma-like carcinoma, ovarian cystadenocarcinoma, and nasopharynx carcinoma metastasis). The clinical characteristics of pathologically diagnosed HCC patients were similar (P > 0.05) compared to non-HCC patients except for higher rate of history of alcoholism (P < 0.05) observed in non-HCC patients. Four of 18 non-HCC patients (22.2%) showed diagnostic discordance on the dynamic imaging study. Despite the recent progression in diagnostic imaging techniques, 2.2% of cases were false-positively diagnosed as HCC in a liver resection patient cohort; and the final diagnosis was benign disease in 0.8% of liver resection patients clinically diagnosed with HCC.