Hepatic vein thrombosis in amoebic liver disease

Clinical History

A 61-year old male patient presented with fever of 10 days duration and worsening right upper quadrant pain for the past week. His laboratory parameters revealed elevated ESR total leucocyte count of 25,000 cu mm and serum bilirubin of 2 mg/dl.

Imaging Findings

Contrast enhanced CT of abdomen revealed a 6 x 6 cm sized peripherally enhancing abscess in the right lobe of liver with associated mild perilesional oedema. This was associated with a linear non-enhancing filling defect (non-occlusive thrombus) in the middle hepatic vein. The remaining hepatic parenchyma and right and left hepatic veins were unremarkable. Additionally, irregular caecal and ascending colonic wall thickening was seen with few enlarged mesocolic nodes in the right iliac fossa. The constellation of imaging findings suggested the possibility of amoebic colitis with amoebic liver disease (hepatic abscess with hepatic vein thrombosis). Differential diagnosis of pyogenic liver abscess with hepatic vein pylephlebitis (thrombophlebitis) was also entertained. The diagnosis of amoebiasis was confirmed based on the amoebic serology (Entamoeba IgG) and positive stool tests.

Discussion

Amoebiasis is an intestinal infection caused by the protozoan parasite Entamoeba histolytica. Amoebiasis continues to be a major public health problem especially in developing countries chiefly due to suboptimal sanitation levels and poorer socioeconomic conditions. Travel to endemic areas, migration of people from endemic region and increase in the prevalence of HIV-AIDS patients have contributed to an increase in the number of cases in the developed countries. Amoebic liver abscess is the commonest extraintestinal complication of amoebiasis. Vascular complications of hepatic amoebiasis are relatively rare with limited reports available in the medical literature [2-7]. We present a previously healthy patient who presented to us with right upper abdominal pain and fever and was diagnosed to have amoebic colitis complicated with a liver abscess and hepatic vein thrombosis.

Vascular complications such as venous thrombosis in amoebiasis are relatively uncommon. They are relatively more frequent in patients with pyogenic liver abscess. Syed MA et al studied contrast enhanced CT examinations of 67 patients with pyogenic liver abscess and discovered venous thrombosis in 28/67 patients (42%). Venous thrombosis involved the portal vein in 24% and hepatic vein in 22%; while 4% had both portal and hepatic venous thrombosis [1]. In contrast, complication such as venous thrombosis associated with amoebiasis is quite rare [2-7]. Zia-ur-Rehman has recently reported extensive thrombosis of the hepatic veins and inferior vena cava in a patient with a large amoebic liver abscess which also extended into the right atrium [2]. An early diagnosis by contrast-enhanced CT examination led to timely percutaneous drainage of abscess and initiation of intravenous metronidazole. The patient could be optimally treated with sternotomy and thrombectomy under peri-operative anticoagulation cover [2]. The exact cause of vascular thrombosis is not known, but probably the inflammatory process induces intra-luminal thrombosis within the hepatic veins or inferior vena cava [3]. Few cases of grave complications such as secondary Budd-Chiari syndrome due to hepatic venous outflow obstruction in amoebiasis have also been reported in the literature [3, 6].

Thus it is imperative for the radiologist to be watchful to the vascular complications of hepatic amoebiasis, as early diagnosis and timely management are crucial for arresting disease progression and optimal therapeutic outcome. Although there are no well-defined therapeutic guidelines available [3]; a combination of medical management (anti-amoebic drugs), percutaneous abscess drainage, and thrombolysis with or without thrombectomy have been tried [2-7].

Differential Diagnosis List

Final Diagnosis

Hepatic vein thrombosis in amoebic liver abscess

URL:	https://www.eurorad.org/case/9489
DOI:	10.1594/EURORAD/CASE.9489
ISSN:	1563-4086