amebic liver abscess

Amebic liver abscess is caused by trophozoites of Entamoeba histolytica entering the liver through the bloodstream from intestinal lesions, leading to hepatic necrosis. It is in fact the most common complication of amebic colitis, with main clinical manifestations including prolonged fever, right upper abdominal or right lower chest pain, systemic wasting, hepatomegaly with tenderness, and leukocytosis, and it tends to cause thoracic complications. Based on inpatient statistics, patients with amebic liver abscess account for approximately 40% of those with amebic colitis. The time from onset of colitis to development of liver abscess ranges from as short as 10 days to as long as over 20 years. According to some statistics, 60% occur within 4 years. Because this period is relatively long and many individuals have mild symptoms during enteritis, only 50% or fewer of patients with amebic liver abscess can recall a history of diarrhea. Radionuclide studies have demonstrated that blood from the superior mesenteric vein predominantly returns to the right hepatic lobe, while blood from the inferior mesenteric vein predominantly returns to the left hepatic lobe. The ileocecal region and ascending colon are the predilection sites of amebic colitis, where the parasites can travel via the superior mesenteric vein to the right hepatic lobe; moreover, the right lobe is larger than the left and receives more blood return. Therefore, clinically, about 90% of abscesses are located in the right lobe, and most are at its superior aspect. The main complications of amebic liver abscess are rupture into surrounding organs and secondary bacterial infection. Internationally, only 40% of pathologically confirmed amebic liver abscess cases are diagnosed antemortem; in China in recent years, the clinical misdiagnosis rate has ranged from 17% to 38.5%. Amebic liver abscess has a prolonged disease course, and patients generally have poor systemic condition, often with anemia and malnutrition. Nutritional and general supportive therapy should be strengthened, with a diet high in carbohydrates, high in protein, high in vitamins, and low in fat. Plasma and albumin may be supplemented when necessary, along with antibiotic therapy. The main treatment measures include administration of anti-amebic drugs, supplemented by percutaneous aspiration of pus, and surgical treatment when necessary.