Amebic Abscess Research Articles

Intracranial Amebic Abscesses

The CT and magnetic resonance findings in a case of intracranial amebic abscesses are described. Due to increased travel to endemic areas, amebic abscess should also be included in the differential diagnosis for patients who live in the temperate parts of the world.

Evaluation of CA 125 as a serum marker of hepatocellular carcinoma

Serum CA 125 concentrations were raised in 90.4% of 115 southern African black patients with hepatocellular carcinoma. Seventy-four percent of 62 patients with amebic hepatic abscess, 60% of 40 patients with chronic hepatic parenchymal disease (chronic hepatitis or cirrhosis), and 60.9% of 41 patients with acute viral hepatitis also had raised values. The median serum CA 125 concentration for patients with hepatocellular carcinoma differed significantly from the benign hepatic disease groups analysed (p less than 0.0002). Serum alpha-fetoprotein levels were raised in 90.4% of the 115 hepatocellular carcinoma patients. CA 125 is thus a highly sensitive marker for hepatocellular carcinoma, but lacks specificity.

Surgical management of hepatic abscesses

Amebic and pyogenic hepatic abscesses are rare liver lesions that may require surgical intervention. Amebic liver abscesses are more common in subtropical and tropical climates and in areas with poor sanitation. The majority of pyogenic liver abscesses are caused by infections in the biliary or intestinal tracts. These lesions can be differentiated on clinical grounds and by amebic serology. Ultrasound and computed tomography are the imaging techniques of choice. The initial management of amebic hepatic abscesses is treatment with amebicidal agents. Most patients respond rapidly so that surgery is reserved for patients with complications including secondary bacterial infection, impending rupture, or rupture into the pericardium or peritoneum. Patients with pyogenic hepatic abscesses require a prolonged course of antibiotics and appropriate drainage. Selected solitary abscesses can be managed with percutaneous abscess drainage. Similarly, some abscesses of biliary origin will respond to percutaneous biliary drainage. Surgical drainage has several advantages including: the ability to explore the abdomen for a source, excellent exposure of the entire liver, accurate assessment, sometimes with ultrasound, of the best drainage site, and access to the biliary tree for cholangiography and drainage.

The 96-kilodalton antigen as an integral membrane protein in pathogenic Entamoeba histolytica: potential differences in pathogenic and nonpathogenic isolates

A surface antigen (EH-96) of Entamoeba histolytica was demonstrated to be a plasma membrane antigen by immunoprecipitation of metabolically 35S-labeled antigen from live trophozoites, Triton X-114 detergent extracts, and plasma membrane-enriched fractions prepared by concanavalin A membrane stabilization and differential centrifugation. In addition, the antigen was localized to the plasma membrane by electron microscopy with colloidal gold. Antigen from E. histolytica strains immunoprecipitated with specific immunoglobulin M (IgM) or IgG2b monoclonal antibody was identical by one-dimensional peptide mapping with N-chlorosuccinimide. Additionally, antigen from different axenically cultivated amebae was demonstrated to be identical by N-chlorosuccinimide peptide mapping, as were peptide maps of IgG and IgM monoclonal antibody-purified antigen. The 96-kilodalton (kDa) surface antigen was identified on four axenically cultivated pathogenic isolates and on three polyxenically cultivated pathogenic isolates (zymodeme II) of E. histolytica but was absent or present in lesser quantity on six nonpathogenic polyxenically cultivated isolates. The 96-kDa antigen was detected in liver abscess fluid from four patients with amebic abscesses by enzyme-linked immunosorbent assay (ELISA) and immunoprecipitation. Two-dimensional gel electrophoresis profiles of the 96-kDa antigen purified from abscess material or from polyxenically cultivated trophozoites demonstrated that the antigens were related to the 96-kDa antigen found in axenically cultivated organisms.

CLINICAL STUDY OF 10 CASES WITH LIER ABSCESS

A series of ten patients with liver abscess during the past 6 years (1982-1987) was subjected to an analitical study of diagnosis, treatments and prognosis of the disease. Of the 10 patients, with the average age of 57.7 years and the male-to-female ratio of 6-4, nine had pyogenic abscesses and the rest one amebic abscess. The source of infection in 6 out of the 9 pyogenic abscesses might be of biliary except the remaining 3 in which the causes were unknown. Each 5 patients had single or multiple abscess respectively, and the abscesses in 7 patients were located in the left lobe and the other 3 in the right lobe. Of the 10 patients, 6 underwent hepatic resections and 4 were amenable to surgical drainage. Seven patients with benign abscess were all healed, but the others related to malignant diseases all died. Liver abscess was once a life-threatening diease, but recent development of techniques in diagnosis and treatment have reduced the mortality in benign cases. But the cases related to malignancies have poor outcomes and are sometimes difficult to diagnose. Hence it is necessary to think about a possible accompaniment of malignancies in treating patients with liver abscess.

Diagnosis and treatment of hepatic amebic abscess in children: R.S. Bennion, E.A. Ramirez, and J.E. Thompson, Jr. Pediatr Surg Internat 4:90–94, (February), 1989

Diagnosis and treatment of hepatic amebic abscess in children: R.S. Bennion, E.A. Ramirez, and J.E. Thompson, Jr. Pediatr Surg Internat 4:90–94, (February), 1989

Liver Abscesses

Clinical suspicion of a liver abscess mandates an investigation of the liver for evidence of a liver abscess by radionuclide, ultrasound, or CT scan. Amebic abscesses have a lower mortality rate than pyogenic abscesses. Amebic and pyogenic abscesses can be distinguished on the basis of epidemiologic, clinical, and laboratory studies. The definitive studies for identifying amebic liver abscesses are hemagglutinin or gel diffusion studies. Amebic abscess of the liver may be complicated by extension to the lung, with pulmonary complications. Patients suspected to have amebic abscesses require metronidazole. Emetine or chloroquine may be added if there is no response or if the abscess recurs. Unless there is a failure of the amebic abscess to resolve or secondary infection occurs, there is seldom a need to aspirate or drain these abscesses. Pyogenic abscesses should be treated with broad-spectrum antibiotics to cover gram-negative aerobes and anaerobic organisms. All pyogenic abscesses larger than 1.5 cm in diameter should be aspirated, and the aspirate should be Gram stained and cultured. Percutaneous or surgical drainage should then be performed. Operative intervention is required in those patients with intra-abdominal pyogenic infections that are seeding the liver abscess. The marked reduction in the mortality rate of pyogenic liver abscess witnessed in this decade is multifaceted and attributable in part to earlier diagnosis, permitting definitive treatment in a timely fashion, as well as to improved intensive unit care, antibiotic management, and operative technique.

Resolution of Liver Abscesses: Comparison of Pyogenic and Amebic Liver Abscesses

To examine the resolution of liver abscesses, a prospective ultrasonographic follow-up study was conducted in 51 patients, each with a solitary abscess (26 pyogenic and 25 amebic) which had been treated successfully by non-surgical measures. The rate of complete abscess resolution for each of the initial 6 months was 0%, 5%, 10%, 23%, 30%, and 30% in the amebic group; and 20%, 54%, 77%, 89%, 94%, and 94% in the pyogenic group. The absorption volume of the pyogenic group in the first month was also greater than that of the amebic group (3.0 +/- 5.0 ml/day vs. 1.1 +/- 0.8 ml/day, P less than 0.05). The resolution ratio of pyogenic and amebic liver abscesses in the first month was 74% +/- 38% and 36% +/- 23%, respectively. In 3 patients in the amebic group, the abscess was still detectable 2 years after treatment. These results suggest that pyogenic liver abscesses resolve more rapidly than amebic abscesses. These findings should be considered in the differential diagnosis of asymptomatic space-taking lesion in the liver.

Therapy of Entamebiasis

Therapy of entamebiasis is critical in that, if untreated, the disease can be fatal. Recently, a new method for differentiating pathogenic and non-pathogenic amebae has been standardized. This method relies upon the electrophoretic analysis of 4 isoenzymes which allow the identification of 20 different zymodemes. It is now widely accepted that non-pathogenic strains of Entamoeba histolytica are not a hazard for humans and therefore don't need therapy. As a consequence, treatment must be addressed only toward infections caused by pathogenic strains. As there are different drugs available for treating amebiasis, from a therapeutical point of view the disease must be divided into two forms: intestinal and extraintestinal. For the former, drugs which reach therapeutical levels in the gut are required. The mainstay for the treatment of asymptomatic carriage of pathogenic strains is DILOXANIDE FUROATE, a very well tolerated luminal amebicide. METRONIDAZOLE and other 5-nitroimidazole compounds such as ORNIDAZOLE are indicated for the treatment of symptomatic intestinal infections as they reach good concentrations in tissues, including the bowel where ulcerations develop. In order to ensure the clearance of amebae from the gut, a subsequent cycle with diloxanide furoate is advisable. Extraintestinal forms include amebic abscesses which can develop in many sites, but most commonly in the liver. Metronidazole and related compounds are the drugs of choice; in case of liver abscess, the addition of CHLOROQUINE is indicated because of its good concentration in tissues. A subsequent cycle with diloxanide furoate is also indicated.(ABSTRACT TRUNCATED AT 250 WORDS)

The CT appearance of cystic masses of the liver.

The authors here discuss twelve discrete pathologic entities that they found, in a review of over 500 abdominal CT scans, caused the appearance of a cystic lesion in the liver. The CT characteristics of the various lesions are illustrated, differential points in the patients' histories are noted, and gross and microscopic pathology specimens are correlated with the CT appearances to explain the CT findings. Lesions considered include: simple (bile duct) cyst, adult polycystic kidney disease, Caroli disease, pyogenic abscess, echinococcal cyst, amebic abscess, metastasis, biliary cystadenoma and cystadenocarcinoma, hepatocellular carcinoma, cholangiocarcinoma, biloma, and extrapancreatic pseudocyst.

Diagnosis and treatment of hepatic amebic abscess in children

From 1 January 1976 to 31 December 1985, 11 children under the age of 12 years (range 11 months to 11 years) were treated for hepatic amebic abscess at the UCLA-affiliated hospitals with no mortality. There were 7 girls and 4 boys, and all were of Mexican or Mexican-American descent. In only 3 instances (27%) was the correct diagnosis considered on admission. In 3 patients the diagnosis was made when symptoms persisted following a negative laparotomy for appendicitis, but all 3 made a complete recovery on medical therapy. A delay in diagnosis in 2 other patients contributed to intrahospital rupture of the abscess and resultant urgent surgical drainage. In the remaining 6 patients, amebicidal therapy alone proved effective and no surgery was required. The complex of fever, abdominal pain, anemia, leukocytosis, and elevated erythrocyte sedimentation rate in a child without a definite diagnosis should prompt the clinician to entertain an early diagnosis of amebic liver abscess and to begin immediate therapy with a safe and efficacious drug.

Perforated amebic liver abscesses: successful percutaneous treatment.

Perforation of hepatic amebic abscess is associated with high morbidity and may result in death. Traditional treatment has been emergency surgery. The authors report successful percutaneous drainage of perforated hepatic amebic abscesses in five severely ill patients. These perforations resulted in abscesses in the subhepatic space, pelvis, chest, right and left paracolic gutters, lesser sac, retroperitoneum, and flank. A total of ten intrahepatic abscesses also were drained in these patients. Catheter drainage lasted from 7 to 34 days and was combined with metronidazole therapy; the latter had been used for 1 week in two patients and in one patient for 2 days without success before drainage. Associated fistulas were demonstrated to the bile ducts, duodenum, and colon; all healed spontaneously. This experience suggests an expanded use of catheter drainage for perforation, a serious complication of amebic abscess.

Echo-guided percutaneous puncture: a safe and valuable therapeutic tool for amebic liver abscess.

To clarify the therapeutic role of echo-guided percutaneous puncture (EPP) in management of amebic liver abscess, 20 patients (24 abscesses) received metronidazole plus EPP. Fluid was aspirated through Chiba needles under real-time sonographic guidance so as to reduce cavity size to less than 3 cm. Not more than two EPPs were necessary in the majority of cases and no complication followed the procedure. This scheme resulted in a shortening of time of both hospitalization (less than or equal to 20 days) and liver lesion healing as assessed by ultrasound (less than or equal to 4 months). It is concluded that EPP is a valuable and safe therapeutic tool for hepatic amebic abscess.

Pyogenic and amebic abscesses of the liver.

Pyogenic and amebic abscesses of the liver.

CT of amebic liver abscess.

CT findings in 23 patients with amebic liver abscess were analyzed retrospectively. A solitary abscess was present in 17 patients. Five patients had two to five lesions. One patient, a male homosexual, had 15 abscesses. Of the 46 abscesses, 74% occurred in the right lobe. The lesions were generally round or oval. One-half of the abscesses were 2-6 cm in diameter; 11% measured 13-16 cm. An enhancing wall was present in most cases. An incomplete rim of edema was seen in eight abscesses. The margin of the abscess was smooth in 63% and nodular in 37%. Internal septations were noted in 30%. Four patients had focal intrahepatic biliary dilatation peripheral to an abscess. One patient had intraabscess hemorrhage. Extrahepatic abnormalities were present in 18 patients; right pleural effusion (nine), perihepatic fluid collection (five), gastric or colonic involvement (eight), and retroperitoneal extension (one). Gas within an abscess was due to hepatobronchial fistula in one patient and hepatocolic fistula in another. Amebic abscess should be included in the differential diagnosis when CT shows one or more cystic or complex masses in the liver, especially when there is evidence of extrahepatic extension.

Amebic liver abscess: MR imaging.

Hepatic magnetic resonance (MR) imaging was performed in 12 patients with 13 amebic liver abscesses. While no specific image or intensity pattern was noted, most lesions were round or oval with smooth, well-defined margins; had decreased signal intensity compared with that of liver parenchyma on T1-weighted images and increased signal intensity on T2-weighted images; and had prominent, often multiple rims of variable signal intensity. Signal homogeneity within the abscess was present more often on T1- than on T2-weighted images. Diaphragmatic disruption was seen in two cases on coronal MR images. An amebic empyema was differentiable from sympathetic pleural effusions by its hyperintensity on both T1- and T2-weighted images. In patients who also underwent computed tomography (CT) or ultrasonography (US), no lesion was missed with any modality, and except for shape, no consistent features were found among images obtained with the different modalities. The data suggest that CT, US, and MR imaging are comparably effective in the detection of amebic abscess.

Enterogastric reflux in suspected acute cholecystitis.

Ninety patients undergoing Tc-99m disofenin hepatobiliary scintigraphy for suspected acute cholecystitis were assessed for enterogastric reflux. Seventy-seven cases showed bowel activity by one hour and were included in the study. Twenty-six percent (20/77) showed definite enterogastric reflux. The gastric activity tended to clear rapidly, even though patients remained supine during examination. Six of 20 patients (30%) with enterogastric reflux had gallbladder visualization. Of these six, one had acute cholecystitis and one had resolving acute cholecystitis with gallstone pancreatitis. There was one case each of pancreatitis, amebic abscess, sepsis, and one normal. Thus, of 20 patients with enterogastric reflux, 16 had acute cholecystitis (80%). Twenty-three of seventy-seven patients (30%) had surgically proven acute cholecystitis: of these, 16 of 23 (70% sensitivity) had gastric reflux, and 50 of 54 without acute cholecystitis did not have reflux (93% specificity). The overall accuracy of enterogastric reflux for acute cholecystitis is 86%. Gastric reflux seen on cholescintigraphy is a secondary sign of acute cholecystitis. Reflux may be related to duodenal irritation from the adjacent inflamed gallbladder.

A selection of photographs from the 1986 A/S/G/E Learning Corner

1. This laparoscopic view of the left lobe of the liver was obtained in a patient with filling defects on liver/spleen scan and a long history of alcohol abuse. Which of the following are true regarding this lesion? a. Needle or pinch forceps biopsy should be diagnostic. b. These nodules are compatible with either primary or secondary tumor in the liver. c. This appearance is common for regenerating nodules of cirrhosis. d. Ct-Fetoprotein is of interest. 2. A patient underwent laparoscopy for evaluation of filling defects seen on CT scan. She had had a breast cancer resected 10 years ago. This view of the underside of the left lobe of the liver showed: a. metastatic tumor b. ectopic gallbladder c. benign appearing cyst d. bulging of amebic abscess 3. This view was obtained in the sigmoid colon in a patient with left lower quadrant pain. The differential diagnosis of this ulcerated mass lesion should include: a. colon cancer b. ulcerated benign tumor such as leiomyoma c. diverticulitis with ulceration of tip of mucosal fold d. solitary rectal ulcer 4. This lesion was seen· in the cecum of an elderly patient with gastrointestinal bleeding. Which of the following are true? a. The lesion probably represents an ulcerated carcinoma and surgical resection is the best therapy. b. The smooth contours favor a lipoma with ulceration. c. Metronidazole is the drug of choice for this ameboma. d. Deep endoscopic biopsies probably would show a naked fat sign. 5. This is a view in the sigmoid colon in a patient with painless rectal bleeding. This shows a. an imbedded foreign body b. a darkly stained Ascaris c. focal linear melanosis coli d. stool which has assumed a linear contour 6. A 57-year-old male underwent polypectomy of a benign appearing I-em adenoma. Eleven days after the procedure the patient returned with rectal bleeding and this lesion was seen at what was thought to be the polypectomy site. Which of the following are true in regard to the demonstrated endoscopic findings? a. This probably represents Crohn's disease and the polyp was really a pseudopolyp. b. Bleeding is occurring from the polypectomy site. c. The best management of this continued bleeding is surgical resection of the involved segment. d. Bleeding occurring 11 days after polypectomy is too long an interval for the prior endoscopic procedure to have been related to the current bleeding. 7. Which of the following is true regarding this view of the distal esophagus?

Amebic Abscess of the Liver

The continued influx of immigrants from Mexico, Central America, and Southeast Asia to the United States has resulted in an increased incidence of several diseases not generally seen in industrialized nations in the twentieth century. One of these is amebic abscess of the liver. This review of the diagnostic features of 57 patients with amebic abscess of the liver treated in one Los Angeles County hospital emphasizes the diagnosis and the versatility of the various roentgenologic approaches and serologic tests.

The value of serum concentrations of tissue polypeptide antigen in the diagnosis of hepatocellular carcinoma

Tissue polypeptide antigen (TPA) is a polypeptide isolated from malignant cells and found in high concentration in the serum of patients with various tumors. No information is available with respect to hepatocellular carcinoma (HCC). Serum TPA concentrations were measured in 290 patients with HCC, 85 healthy controls, 33 patients with amebic hepatic abscesses, 43 with chronic hepatitis or cirrhosis, and 39 with acute hepatitis. Raised values were found in 96% of the HCC patients, but also in 61% of patients with amebic abscesses, 86% with chronic hepatic parenchymal disease, and 90% with acute hepatitis. If a cut-off level of 500 IU/L was used, this reduced the sensitivity of TPA in HCC to 46%, but still left 46% of patients with acute hepatitis with raised values. TPA is comparable in sensitivity with alpha-fetoprotein as a marker for HCC, but its lack of specificity severely limits its clinical usefulness.