Ultrasound and Clinicopathological Study of Steatohepatitic Hepatocellular Carcinoma

Abstract

Purpose: Steatohepatitic hepatocellular carcinoma (SH-HCC) is a newly described subtype of HCC as defined in the 2019 World Health Organization (WHO) classification of tumors. In this study, ultrasound and clinicopathologic studies were conducted on patients who were diagnosed with SH-HCC. SH-HCC has been associated with liver cancer resulting from fatty liver disease; this condition has been identified in an increasing number of patients in recent years. Subjects and Methods: This study included 34 patients in the typical SH-HCC group (7%) and 37 patients in the focal SH-HCC group (8%) out of 477 patients who underwent curative resection of untreated HCC during 2015-2019. We conducted a retrospective clinicopathological study focusing on ultrasound B-mode images. Results and Discussion: The median diameter of the lesions associated with typical SH-HCC was 18 mm. Most of the HCCs were moderately differentiated: 67% exhibited a hyperechoic pattern, 33% presented with a nodule in a nodule pattern, and 83% had a marginal hypoechoic layer. A lateral shadow was detected in 80% of the tumors. Acoustic shadows appeared in 87%. Dynamic computed tomography/magnetic resonance imaging revealed hypervascularity in the arterial phase and washout of contrast medium during the late portal phase; these findings are consistent with normal HCC with fat deposition. By contrast, 69% of those from the focal group presented with findings that were consistent with the ultrasound diagnostic criteria of the Japan Society of Ultrasonics in Medicine for nodules associated with hepatic masses. In both cases, the background liver tissue was notable for advanced fibrosis. Approximately one-third of the background liver tissue included findings consistent with fatty liver; this had a significant impact on B-mode findings or generated difficulties with visualization in the 10% range. Conclusion: Typical SH-HCC showed characteristic B-mode findings, which showed that it is possible to distinguish SH-HCC using ultrasonic images.