Portal venous perfusion steal causing graft dysfunction after orthotopic liver transplantation: serial imaging findings in a successfully treated patient

A 53-year-old male with hepatocellular carcinoma underwent orthotopic liver transplantation. Preoperative computed tomography revealed main portal vein luminal narrowing by flat thrombi and the development of cavernous transformation. On post-transplantation day 1, thrombotic portal venous occlusion occurred, and emergency thrombectomy was performed. Subsequent Doppler ultrasonography and contrast-enhanced ultrasonography confirmed the restoration of normal portal venous flow. The next day, however, decreased portal venous velocity was observed via Doppler ultrasonography, and serum liver enzymes and bilirubin levels remained persistently elevated. Direct portography identified massive perfusion steal through prominent splenorenal collateral veins. Stent insertion and balloon angioplasty of the portal vein were performed, and subsequent Doppler ultrasonography demonstrated normalized portal flow parameters. Afterwards, the serum liver enzymes and bilirubin levels rapidly normalized.

Necrotic lymphoma in a patient with post-transplantation lymphoproliferative disorder: ultrasonography and CT findings with pathologic correlation

Seventeen months after kidney transplantation for the treatment of nephrotic syndrome, a retroperitoneal mass was incidentally detected in a 30-year-old man during routine follow-up. Ultrasonography revealed a mass measuring 5.5 cmx4.3 cm located between the liver and the atrophic right kidney, which showed markedly heterogeneous internal echogenicity. Contrast-enhanced computed tomography displayed a mild degree of enhancement only at the periphery of the mass, while the center lacked perceivable intensification. The patient underwent surgical resection. The final pathological diagnosis was non-Hodgkin lymphoma (diffuse large B-cell lymphoma), and extensive necrosis was observed on microscopic examination. We found that the prominent heterogeneous echogenicity of the mass (an unusual finding of lymphoma) demonstrated on ultrasonography is a result of extensive necrosis, which may sometimes occur in patients with post-transplantation lymphoproliferative disorder.