Low specificity of washout to diagnose hepatocellular carcinoma in nodules showing arterial hyperenhancement in patients with Budd-Chiari syndrome

Abstract

It remains unclear whether the classic imaging criteria for the non-invasive diagnosis of hepatocellular carcinoma (HCC) can be applied to chronic vascular liver diseases, such as Budd-Chiari syndrome (BCS). Herein, we aimed to evaluate the diagnostic value of washout for the discrimination between benign and malignant lesions in patients with BCS. This retrospective study included all patients admitted to our institution with a diagnosis of BCS and focal lesions on MRI from 2000 to 2016. MRI images were reviewed by 2 radiologists blinded to the nature of the lesions. Patient and lesion characteristics were recorded, with a focus on washout on portal venous and/or delayed phases. Lesions were compared using Chi-square, Fisher's, Student's t or Mann-Whitney U tests. A total of 49 patients (mean age 35 ± 12 years; 34 women [69%] and 15 men [31%]) with 241 benign lesions and 12 HCC lesions were analyzed. Patients with HCC were significantly older (mean age 44 ± 16 vs. 33 ± 9 years, p = 0.005), with higher alpha-fetoprotein (AFP) levels (median 16 vs. 3 ng/ml, p = 0.007). Washout was depicted in 9/12 (75%) HCC, and 69/241 (29%) benign lesions (p <0.001). A total of 52/143 (36%) lesions ≥1 cm with arterial hyperenhancement showed washout (9 HCC and 43 benign lesions). In this subgroup, the specificity of washout for the diagnosis of HCC was 67%. Adding T1-w hypointensity raised the specificity to 100%. A serum AFP >15 ng/ml was associated with 95% specificity. Washout was observed in close to one-third of benign lesions, leading to an unacceptably low specificity for the diagnosis of HCC. The non-invasive diagnostic criteria proposed for cirrhotic patients cannot be extrapolated to patients with BCS. Washout on MRI is depicted in a significant proportion of benign nodules in patients with Budd-Chiari syndrome (BCS), limiting its value for the differentiation between benign and malignant lesions. Criteria proposed for the non-invasive diagnosis of hepatocellular carcinoma in patients with cirrhosis cannot be extrapolated to patients with BCS. Additional imaging findings and patient characteristics, including alpha-fetoprotein serum level, can help determine the probability of a nodule being HCC in patients with BCS.