Amoebic liver abscess and disturbances of portal circulation

Branch portal vein pyaemia secondary to amoebic liver abscess

We describe a case of a young returning traveller who contracted amoebic dysentery while visiting India. She presented to a major London Hospital several months later with features suggestive of amoebic liver abscesses, a known sequelae of amoebiasis. MRI with intravenous contrast demonstrated an area of likely occlusion of the portal vein. The patient was treated with intravenous metronidazole for 10 days followed by diloxanide furoate, an intraluminal agent. The largest abscess was drained acutely under ultrasound guidance. The portal vein occlusion was treated medically without the use of anticoagulation. A repeat ultrasound at 6 weeks post-treatment confirmed patency of the portal vein indicating spontaneous recanalisation with antimicrobial therapy alone.

Amebic liver abscess

Amebic liver abscess is the most common extraintestinal manifestation of infection with Entamoeba histolytica, and it is associated with significant morbidity and mortality. In this article the most recent available information is reviewed relating to epidemiology, pathogenesis, presentation, diagnosis, and treatment. We reviewed thousands of cases of amebic liver abscess in the medical literature and present that information as it pertains to mortality, gender, anatomic location of abscesses, and clinical signs and symptoms.

Amebic liver abscess

Amebiasis is a widespread parasitic disease caused by Entamoeba histolytica. This protozoan organism is the third leading parasitic cause of death in the developing world and is an important health risk to travelers in endemic areas. Amebiasis most commonly results in asymptomatic colonization of the gastrointestinal tract, but some patients may develop intestinal invasive disease or extraintestinal disease-amebic liver abscess being the most common extraintestinal manifestation. This article reviews epidemiologic features, pathophysiology, clinical features, diagnostic tests, imaging studies, treatment of amebic liver abscess, and prevention measures.

Entamoeba histolytica: antibody responses and lymphoreticular changes in gerbils (Meriones unguiculatus) in response to experimental liver abscess and amebic extract infection

Antibody responses and histological changes in hepatic lymph nodes and spleen of gerbils (Meriones unguiculatus) during the course of experimental hepatic amebiasis (5-60 days), or in those injected with extracts of Entamoeba histolytica, are described. Lymph node and spleen responses in infected animals paralleled the proliferation of the amebic liver abscess. However, spleen follicle responses were similar in animals that received low or high doses of the amebic extract and differed histologically from those with amebic liver abscess. Liver abscesses, up to 30 days postinfection (pi), doubled in weight between 10 and 15 and between 20 and 30 days pi. Early changes (10 days pi) in the lymphoreticular tissues were characterized by increased size and weight of the organs, hyperplastic follicles, and blastogenesis in the T-dependent areas. At 20 and 30 days pi, the size of spleen follicles increased and there was depletion of lymphocytes from the periarterial area (PAA), as well as gross extension of the red pulp, accompanied by extramedullary erythropoiesis and megakaryocytosis. The paracortical areas (PCA) of lymph nodes were depleted of lymphocytes and histiocytosis throughout the organ, and there was intense plasma cell activity in the medulla. At 60 days pi, lymphocyte repopulation was noted in the PCA and PAA; germinal centers were depleted of blast cells and the spleen red pulp had contracted. Antiamebic antibody titers were low throughout the infection. Changes in the cellularity of the lymphoid organs are discussed in relation to the proliferation of the amebic liver abscesses in infected animals and in those which were injected with the amebic extract.

The pathology and pathogenesis of fatal hepatic amoebiasis--A study based on 79 autopsy cases

The present study is based on a retrospective analysis of 79 autopsy cases of hepatic amoebiasis. An attempt has been made to reconstruct the sequence of events starting from intestinal infection to invasion and transport of amoebae along the radicles of the portal veins, the formation of early Zahn's infarct and the proliferation of amoebae in such foci leading to the formation of small abscesses. The coalescence of small abscesses gives rise to the apparently large abscesses. Apart from direct contiguity, more distant extension leading to a satellite abscess is due to involvement of the hepatic and/or portal venous radicles. It seems that obstruction of the hepatic vein contributes substantially towards the enlargement of the liver and its exaggerated nutmeg appearance. Signs and symptoms of hepatic vein obstruction sometimes overshadow the abscess pathology. Thrombosis or pressure of a neighbouring abscess over the portal vein obstruction sometimes overshadow the abscess pathology. Thrombosis or pressure of a neighbouring abscess over the portal vein and bile-duct lead to development of portal hypertension and jaundice. Both cell-mediated and humoral immunity are depressed in fatal cases of hepatic amoebiasis.