Large well-differentiated hepatocellular carcinoma in patients with HBV: gadoxetic acid-enhanced MR imaging features and prognosis.

[OBJECTIVE] To explore the gadoxetic acid-enhanced MR imaging features and prognosis of large well-differentiated hepatocellular carcinoma (LWDHCC) (≥ 3 cm) in patients with HBV.

[MATERIALS AND METHODS] One hundred and eighty-two patients with HBV-related HCC (≥ 3 cm) who underwent gadoxetic acid-enhanced MR scanning and surgical resection were included in this retrospective study, 31 were defined as LWDHCC and 151 as typical HCC. Clinicopathologic characteristics and gadoxetic acid-enhanced MR imaging features were evaluated. The Kaplan-Meier method and Cox proportional hazards model were used to analyze recurrence-free survival (RFS), overall survival (OS).

[RESULTS] LWDHCCs had a lower incidence of microvascular invasion (29% vs 56%, p = 0.021), and none of them were classified as macrotrabecular-massive or steatohepatitic subtype. LWDHCCs showed transitional-phase (TP) washout more frequently (32% vs 17%, p = 0.004) or did not washout (26% vs 11%, p = 0.004). Lesion-to-liver signal intensity ratio during the portal phase of LWDHCC was significantly higher (1.04 ± 0.21 vs 0.85 ± 0.26, p < 0.001). TP hyperintensity (odds ratio, 3.186; p = 0.010) and mosaic architecture (odds ratio, 0.215; p = 0.004) were independent imaging predictors associated with LWDHCC. Portal vein tumor thrombosis (PVTT) (hazard ratio [HR] 0.265, p = 0.024) was an independent predictor of poorer RFS, while PVTT (HR 0.396, p = 0.023) and mosaic architecture (HR 0.286, p = 0.002) were linked to poorer OS.

[CONCLUSION] TP hyperintensity and mosaic architecture were associated with LWDHCC. PVTT and mosaic architecture were significantly associated with RFS and OS in patients with HBV-related HCC (≥ 3 cm).

[KEY POINTS] Question Gadoxetic acid-enhanced MR imaging features and prognosis of large and well-differentiated HBV-related HCC are unknown. Findings Transitional phase hyperintensity and mosaic architecture were associated with large well-differentiated HCC, portal vein tumor thrombus, and mosaic architecture were associated with prognosis. Clinical relevance The study provides clinicians with a more robust diagnostic and prognostic framework for managing patients with HCC ≥ 3.0 cm, and is helpful to understand the pathogenesis of large well-differentiated HCC, which may not necessarily be multi-step carcinogenesis.