A new study from researchers in China investigated the use of contrast-enhanced ultrasound (CEUS) for the differential diagnosis of poorly differentiated hepatocellular carcinoma (p-HCC) and intrahepatic cholangiocarcinoma (ICC).
The authors investigated the performance of the v2017 CEUS Liver Imaging Reporting and Data System (LI-RADS) to differentiate p-HCC from ICC and also proposed a CEUS signature to improve the differentiation between the 2 liver cancer types.
Using the LR-5 category (definite HCC) of LI-RADS to diagnose p-HCC compared to ICC, the study found area under the curve (AUC), sensitivity, and selectivity values of 0.758, 51.67%, and 100%, respectively. When the authors built a CEUS signature that included washout time and tumor boundary values, the AUC, sensitivity, and selectivity increased to 0.955, 91.67%, and 90.57%, respectively.
Finally, if B-mode ultrasound was added to the CEUS signature to make a new ultrasound (US) signature, the diagnostic values increased to 0.976, 96.67%, and 92.45%, respectively. When compared, the AUC and sensitivity of the CEUS and US signatures were significantly higher than LI-RADS (P <.001).
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Based on the results, the authors concluded, “LR-5 had high specificity but low sensitivity in diagnosing p-HCC. When the washout time and tumor boundary were included in the CEUS signature, the sensitivity and AUC were remarkably increased in the differentiation between p-HCC and ICC.”
Hepatocellular carcinoma (HCC) and ICC are the 2 most common forms of liver cancer but the prognosis of ICC is worse than that of HCC mainly due to high rates of metastasis. Since treatments for HCC are generally ineffective in patients with ICC, their differential diagnosis is extremely important.
Previous studies have shown that a subset of HCCs (p-HCCs) have a significantly shorter washout time than well-differentiated HCCs (w-HCCs) making it easier for them to be misdiagnosed as LR-M (malignancy but not HCC) rather than LR-5 using LI-RADS. Since ICCs are also categorized as LR-M, the differential diagnosis of ICCs and p-HCCs can be difficult and new approaches to their differentiation are critical.
For the study, CEUS scans from a total of 60 patients with p-HCC and 56 with ICC were retrospectively analyzed. Diagnoses of all 60 p-HCC patients were confirmed based on pathological findings after surgical resection while the diagnoses for 51 of the ICC patients were proven by surgical resection and the remaining 5 via biopsy. All ultrasound images were reviewed by 2 radiologists with more than 10 years of experience with liver ultrasound.
Guo H-L, Zheng X, Cheng M-Q, et al. Contrast-enhanced ultrasound for differentiation between poorly differentiated hepatocellular carcinoma and intrahepatic cholangiocarcinoma. J Ultrasound Med. 2021;9999:1-13. doi:10.1002/jum.15812