γδ T cells in liver diseases / 医学前沿

γδ T cells display unique developmental, distributional, and functional patterns and can rapidly respond to various insults and contribute to diverse diseases. Different subtypes of γδ T cells are produced in the thymus prior to their migration to peripheral tissues. γδ T cells are enriched in the liver and exhibit liver-specific features. Accumulating evidence reveals that γδ T cells play important roles in liver infection, non-alcoholic fatty liver disease, autoimmune hepatitis, liver fibrosis and cirrhosis, and liver cancer and regeneration. In this study, we review the properties of hepatic γδ T cells and summarize the roles of γδ T cells in liver diseases. We believe that determining the properties and functions of γδ T cells in liver diseases enhances our understanding of the pathogenesis of liver diseases and is useful for the design of novel γδ T cell-based therapeutic regimens for liver diseases.

Solitary Necrotic Nodules of the Liver Mimicking Hepatic Metastasis: Report of Two Cases

We present two cases of solitary necrotic nodules of the liver which on radiologic images mimicked hepatic metastasis. Solitary necrotic nodule of the liver is a rare but benign entity which histopathologically consists of an outer fibrotic cap-sule with inflammatory cells and a central core of amorphous necrotic material. The lesion was seen on contrast-enhanced CT as an ovoid-shaped hypoattenu-ating nodule; on CT during hepatic arteriography as enhancing nodule; on intra-operative US as a target-appearing hypoechoic nodule; on T2WI as a hyperinten-sity nodule, and on dynamic MR as a subtle peripheral enhancing nodule. Although the radiologic features are not specific, solitary necrotic nodule of the liver should be included in the differential diagnosis of hepatic metastasis.

Focal Hepatic Lesions with Peripheral Eosinophilia: Imaging Features of Various Disease

Due to the recent advent of various imaging modalities such as ultrasonography, computed tomography andmagnetic resonance imaging, as well as knowledge of the characteristic imaging features of hepatic lesions,radiologic examination plays a major role in the differential diagnosis of focal hepatic lesions. However, various'nonspecific' or 'unusual' imaging features of focal hepatic lesions are occasionally encountered, and this makescorrect diagnosis difficult. In such a situation, the presence of peripheral eosinophilia helps narrow the differential diagnoses. The aim of this pictorial essay is to describe the imaging features of various diseaseentities which cause focal hepatic lesions and peripheral eosinophilia.

Hepatic Abscess: Three-Phase Helical CT Appearance

PURPOSE: The purpose of this study was to evaluate the enhancement patterns and morphologic features ofhepatic abscesses, as seen on three-phase helical CT images. MATERIALS AND METHODS: Three-phase helical CT imagesof 22 clinically and pathologically proven hepatic abscesses more than 3 cm in diameter in 21 patients wereretrospectively reviewed. Three-phase helical CT scans were obtained at 30 sec(hepatic arterial phase, AP), 70sec(portal venous phase, PP) and 3 min(equilibrium phase, EP) after the start of intravenous infusion of contrastmaterial. We analyzed the number of abscess layers and their enhancement patterns during each phase, and evaluatedthe size and shape of abscess, the CT attenuation and presence of septae in the abscess cavity, and the thicknessand maturation of the granulation layer and collagenous wall. RESULTS: AP images showed that 13 abscesses(59%)had four layers; on PP images, half the abscesses were seen to have three layers, while EP images showed thattwo-thirds had two layers. Among the 13 abscesses with four layers seen on AP images, all abscess cavities andgranulation layers were hypo- and hyperattenuating, respectively, during all three phases. Most hypoattenuatingcollagenous walls seen on AP images became iso- or hyperattenuating on EP images, while hyperattenuatinghyperperfusion zones seen on AP images became isoattenuating during later phases. The degree of maturation of thecollagenous wall correlated with the number of abscess layers. CONCLUSION: As seen on AP, PP and EP three-phasehelical CT images, hepatic abscess frequently had four, three, or two layers respectively. More mature collagenouswalls tended to have more abscess layers.