Focal hepatic solid lesions incidentally detected on initial ultrasonography in 542 asymptomatic patients

Purpose: The purpose of this study is to evaluate the clinical significance of focal hepatic solid lesions incidentally detected on initial ultrasonography in asymptomatic patients. Methods: From January 2009 to December 2009, 2670 initial ultrasonographies were performed in asymptomatic population. Of these 2670 initial examinations, 681 focal hepatic solid lesions in 542 patients (mean 39.4 years, range 23–73 years) were detected. Clinical information, ultrasonography features, and the outcome of these lesions were analyzed. Results: Six hundred and seventy four lesions (99.0%) in 539 patients (99.4%) were benign, while seven lesions (1.0%) in three patients (0.6%) proved to be malignant. Risk factors significantly associated with malignant focal hepatic solid lesions were known history of malignancy, history of hepatitis, a positive result for the hepatitis B surface antigen, and abnormally elevated tumor markers. No malignancy was identified in patients without any one of these four risk factors. Ultrasonographic features of internal heterogeneous echotexture with peripheral hypoechoic rim showed significant associations with malignancy. Conclusions: Focal hepatic solid lesions incidentally detected on initial ultrasonography were rarely malignant, especially in patients without these risk factors. Therefore, the knowledge of these risk factors and US features is important in order to make a differential diagnosis between benign and malignant focal hepatic lesions.