Displacement of Malignant Cells into the Portal Triad of the Liver Results in Reduced Liver Perfusion, Mimicking Segmental Fatty Liver
We report the case of a 69-year-old male patient who was suffering from a right-sided non-small cell bronchial cancer. The initial PET/CT showed a localized tumor in the right upper lung with 1 PET-positive lymph node in the right and left hili (R 10, L 10), which was confirmed histologically after transbronchial biopsy. There was also 1 histologically proven bone metastasis in the right iliac bone, but no signs of further distant metastasis in the liver or abdomen. The initial stage was cT3, cN3, M1. EGF receptor and K-ras mutation were negative. At the onset of the known disease 4 months earlier, the liver, especially in a routine CT scan, showed no pathological signs or liver metastasis (fig. ). The patient was treated with systemic chemotherapy and was in a generally good condition. Four months later, a sudden elevation of liver enzymes was documented, while 4 months earlier they had been within the normal range. There was an elevation of serum lactate dehydrogenase (636 U/l), carcinoma embryonic antigen (147 U/l), Y-GT (741 U/l) and alkaline phosphatase (645 U/l). At this time, the patient showed no sign of clinical symptoms, especially in the abdomen. A repeat CT of the abdomen was performed in order to investigate the elevation of the liver enzymes. Segmental hypointensity was found in the venous phase in segments 5 and 6, without any occlusion of the central portal vein and hepatic artery (fig. ). A precontrast scan was not performed, but the density in the portal venous phase was 32 Hounsfield units. Our first suspicion was inhomogeneous liver steatosis, but the distribution of this change was atypical and looked bizarre. Having doubts, we performed an ultrasound scan with the application of a contrast medium. The normal B-mode ultrasound shows discrete hyperechogenic regions (fig. ). The additionally performed power Doppler showed reduced vessels in the periphery of segments 5 and 6 (fig. ). After applying a contrast medium, there were clear signs of perfusion deficiency in the early arterial phase without washout in the late phase (fig. ). Because we had problems in making a definitive diagnosis, a core biopsy was performed within this area.\nTo our surprise, histology showed infiltration of the portal triad, which surrounds small portal veins and the hepatic artery within the portal triad. There were also some small metastatic cells within the small portal veins (fig. ). There were no signs of classical liver metastasis or steatosis. Chemotherapy was intensified, but the local changes in the liver did not change at any time, as documented by subsequent CT scans.