Intra-hepatic arterioportal shunt mimicking a metastatic liver tumor: report of a case

Value of precontrast and portal venous phases for evaluating atypical hepatocellular carcinoma mimicking arterioportal shunt

PURPOSE

To evaluate the value of precontrast phase (PP) and portal venous phase (PVP) for differentiation of small hypervascular hepatocellular carcinomas (HCCs) without delayed washout from arterioportal (AP) shunts in high-risk patients of HCC.

METHODS

A total of 122 lesions (73 AP shunts and 49 HCCs) detected on quadriphasic CT in 101 patients with chronic liver disease were analyzed. All lesions (≤2 cm) showed arterial enhancement and isodensity on delayed phase (DP) with exclusion of typical features of AP shunts. Lesion morphologic features (size, location, shape, margin) on biphasic CT (arterial phase and DP), Alpha-fetoprotein (AFP) values and coexistent HCC were evaluated. The qualitative and quantitative analyses of lesion attenuation on quadriphasic CT were performed. Diagnostic performances for prediction of AP shunts over HCC were compared among the biphasic CT, triphasic CT (adding PP or PVP) and quadriphasic CT.

RESULTS

In multivariate analysis, the presence of concomitant HCC (p = 0.0005, odds ratio [OR] = 0.11), visual hypodensity on PP (p = 0.0004, OR = 17.72) and visual hyperdensity on PVP (p = 0.0003, OR = 0.051) were independent predictors for HCCs rather than AP shunts. Additional review of PP and PVP revealed significantly improved diagnostic performance yielding the highest diagnostic performance.

CONCLUSIONS

Hypodensity on PP and hyperdensity on PVP are significant predictive features in differentiating atypical small hypervascular HCC from AP shunts in patients with high-risk of HCC. Careful evaluation of the PP and PVP may reduce underdiagnosis and lead to earlier diagnosis of atypical small HCCs.

Chondroma of the diaphragm mimicking a giant liver tumor with calcification: report of a case

Extraskeletal chondroma is an unusual benign tumor, which rarely arises in the diaphragm. We report a case of chondroma of the diaphragm in a 31-year-old woman. Initially, a benign liver tumor with calcification was suspected, based on pre and intraoperative examination findings. Although parts of the tumor were contiguous with the diaphragm, its connections with the diaphragm were much narrower than its connection with the liver, which suggested a liver tumor. Pathological examination subsequently revealed that the chondroma was contiguous with the diaphragm and that there was a distinct border between the tumor and the liver; thus, the tumor was diagnosed as a chondroma of the diaphragm.