Pathology of pyogenic liver abscess in children

Liver abscesses in the Western pediatric population

Background and study aims: Liver abscesses are rare in the Western pediatric population and data on predisposing factors and etiology are scarce. We aimed to describe predisposing factors, microbiological characteristics, and treatment. Patients and methods: Retrospective analysis of children admitted to two tertiary care hospitals in Belgium from 1 January 1996 to 31 December 2019. We analyzed clinical features, predisposing factors, imaging characteristics, microbiological data, treatment, and outcome in children with a liver abscess and compared these data with the literature. Results: We collected 24 cases with a male to female ratio of 1.4 and a median age of 3.2 years at time of diagnosis. Survival was 95.8%. Invasive culture specimens were obtained in 83.3% and showed growth of bacteria in 55%. Parenteral antibiotics were administered before invasive culture sampling in 80%. Liver abscesses were cryptogenic in four (16.7%) patients. Hepatobiliary disease was the most prevalent predisposing factor (n = 6; 25%), followed by recent antineoplastic therapy for malignancies (n = 5; 20.8%), intra-abdominal surgical pathology (n = 4; 16.7%) and umbilical venous catheters (n = 2; 8.3%). In two patients there was a parasitic origin (n = 2; 8.3%) and in one it was caused by Bartonellosis. There was no diagnosis of chronic granulomatous disease (CGD) in our cohort. Conclusions: Pediatric liver abscesses have a favorable outcome in the developed world. Whenever feasible, invasive abscess culture specimens should be obtained. In patients presenting with a cryptogenic liver abscess or atypical disease course, immunological workup should be ensured.

An unusual abdominal wall mass in a child

Abdominal tumors are one of the most common types of pediatric cancer. Therefore, they should always be included in the differential diagnosis of abdominal masses. Here, we present the case of a child whose initial hypothesis of diagnosis contemplated this possibility. Later, it was demonstrated that the abdominal mass found was secondary to a common parasitosis. A 2-year old, moderately malnourished and pale white boy was referred with a history of a rapidly growing, well-limited, middle abdominal mass. The mass was 10 by 3 cm, hard and poorly movable, apparently involving both abdominal rectus muscles. A complete resection was performed, revealing an abdominal wall abscess, with intense eosinophilic proliferation, secondary to a local and intense reaction to innumerous Ascaris lumbricoides eggs. Extra luminal infestations with Ascaris, that usually form peritoneal granulomas have been previously described. However, neither external trauma nor fistula, that could explain the superficial presence of the eggs, was found. This description reinforces the relevance of infectious diseases within the differential diagnosis of abdominal masses, particularly in areas with high prevalence of parasitic infestations.

[Particularities of liver abscesses in children in Senegal: Description of a series of 26 cases]

Liver abscess is a serious infection that can cause life-threatening complications.

OBJECTIVE

To describe the epidemiology, diagnosis, and progression of liver abscess at the Dakar National Albert-Royer Children's Hospital.

METHOD

A retrospective study was conducted from over a period of 5 years (1st January 2010 to 31st December 2014). All children aged 0-15 years hospitalized for liver abscess with ultrasound confirmation were included. We collected demographic data (age, gender, socioeconomic status, origin), clinical data (general and hepatic symptoms), diagnostic data (ultrasound, bacteriology) and progression (death, complications, sequelae). The data were analyzed with Epi-info (P<0.05 was considered significant).

RESULTS

We collected 26 cases of liver abscesses, representing a hospital prevalence of 100 cases per 100,000 admissions. Males predominated (sex ratio: 1.36). The children's average age was 7.2 years. Most of the children came from urban areas of Dakar. Low socioeconomic status and precarious lifestyle were the contributing factors. Anemia (69.2%), malnutrition (42.3%), and abdominal trauma (15.3%) were the main causes found. The Fontan triad characteristic of the liver abscess was found in 57.7% of cases. At ultrasound, a single abscess was found in 21 cases. The abscess was located in the right lobe in 18 cases, the left lobe in three cases, and in both lobes in three cases. Segment VI (four cases) was the most frequently involved. Bacteriologically, the abscess was pyogenic in 17 cases and an amoebic abscess in nine cases. The main pyogenic sources found were Klebsiella pneumoniae in two cases, Pseudomonas aeruginosa in one case, Streptococcus pneumoniae in one case, and Staphylococcus aureus in one case. The average duration of antibiotic treatment was 14.5 days. Liver drainage was carried out in 24 cases. The outcome was favorable in all children.

CONCLUSION

The prevalence of liver abscesses at the Albert-Royer Children's Hospital is relatively high, compared to the literature data. Percutaneous drainage combined with antibiotics remains the treatment of choice. The prognosis is favorable.

Abscesso hepático de origem hematogênica em paciente com febre de origem indeterminada

OBJETIVO: Descrever uma apresentação atípica de abscesso hepático em paciente pediátrico e realizar uma revisão da literatura no que diz respeito às diferenças observadas na etiopatogenia do quadro, quando considerados os países desenvolvidos e aqueles em desenvolvimento. DESCRIÇÃO DO CASO: Paciente de 13 anos, do sexo masculino, foi trazido ao pronto-socorro pediátrico devido à febre diária e à perda de peso, sem alterações ao exame físico. Na investigação realizada, o ultrassom abdominal evidenciou área heterogênea nodulariforme relativamente definida, compatível com abscesso hepático. Foi realizada drenagem cirúrgica e antibioticoterapia. No material da drenagem houve crescimento de Staphylococcus aureus sensível à oxacilina. COMENTÁRIOS: O caso demonstra a importância de o pediatra conhecer as principais causas da febre de origem indeterminada, saber desenvolver a abordagem investigativa e, frente ao diagnóstico de abscesso hepático, aferir a possibilidade de o agente etiológico ser o Staphylococcus aureus, principalmente quando houver relato de rotura da pele.

Significance of Charcot Leyden crystals in hepatic aspirates

Charcot Leyden crystals are hexagonal bipyramidal structures localised in the primary granules of the cytoplasm of eosinophils and basophils. Their presence, along with eosinophilic infiltrate, is an indirect evidence of parasitic infestation particularly with Toxocara, Capilliriasis, Ascariasis, or Fasciola. We report here two cases where Charcot Leyden crystals with eosinophilic infiltrate were found in the smears prepared from hepatic abscess.

Liver abscess in children: an overview

BACKGROUND

Liver abscess (LA) in the pediatric population has become relatively uncommon in developed countries but it continues to have a high incidence among children in developing countries. This article aims to review the trends in all aspects of LA in children, both temporally and geographically.

DATA SOURCES

The PubMed and Google Scholar database were searched with the keywords "liver abscess", "children", "predisposing causes", "clinical signs and symptoms", "treatment" from 1975 to 2009 and all kinds of retrospective and prospective studies, reviews, case series were included.

RESULTS

Pyogenic LA constitutes the majority of cases, followed by amebic and fungal LA. Staphylococcus aureus is the most common pathogen worldwide. Ultrasonography (US) and computed tomography (CT) are widely used as diagnostic tools. There are varying opinions regarding the treatment of LA in children. The general trend is towards less invasive modalities of treatment like percutaneous drainage along with antimicrobial drug therapy. However, in selected patients, open surgical drainage still plays an important role. The mortality rate for pyogenic LA has shown a decline from about 40% before the 1980s to less than 15% in the recent years. At the same time, the mortality rate of amebic LA cases reported to be around 11%-14% before 1984 has reduced to less than 1% at present.

CONCLUSIONS

Etiological pattern of LA in children has remained the same over the years, and in most regions, it is associated with Staphylococcus aureus and amebic LA is quite uncommon. US or CT scan is the most frequently employed diagnostic modality for LA, and follow-up is usually performed by serial US scans. Antimicrobial therapy along with, if necessary, drainage of the abscess by either percutaneous or open surgical route remains the treatment of choice.

Prevalence of Toxocara-induced liver granulomas, detected by immunohistochemistry, in a series of autopsies at a Children's Reference Hospital in Vitoria, ES, Brazil

The aim of this investigation was to study the frequency of visceral larva migrans (VLM) granulomas in autopsies at a Children's Reference Hospital in Vitoria, ES Brazil, where anti-Toxocara antibodies are frequently detected in the serum of children admitted at the hospital. Two liver fragments from 310 autopsies of children aged between 1 and 15 years were paraffin embedded, and sections were stained with hematoxylin and eosin and submitted to detection of Toxocara antigens using a rabbit anti-Toxocara serum. Among the 24 cases with granulomatous lesions, ten had eosinophil-rich granulomas positively stained with the anti-Toxocara serum. Some were typical epithelioid granulomas, with a positive reaction in multinucleated giant cells, epithelioid cells, or necrotic debris. The results showed that VLM granulomas are the most frequent granulomatous hepatitis in children in our county. This agrees with the high prevalence of anti-Toxocara antibodies in the serum of children admitted to the Children's Reference Hospital. The 3.2% frequency of liver VLM granulomas in autopsies is less than the 30-39% frequency of positive serology in these children, probably reflecting the low larval burden in infected children.

Liver abscess in children

Liver abscesses are frequently observed in pediatric clinical practice in tropics and subtropics especially in developing countries. Children have unique set of predisposing factors which have been highlighted. Expected microbiology and setting for unusual organisms are mentioned. Clinical presentations', including importance of location and number of abscesses has been discussed. Role of each modality of treatment clarified. Importance and limitations of investigations and imaging explained and complications and mortality discussed.

Liver abscesses in children: a single center experience in the developed world

OBJECTIVES

The aim of this study was to investigate the clinical and radiologic features, predisposing risk factors, and complications of children with pyogenic liver abscess (PLA) referred to a tertiary pediatric hepatology center.

METHODS

We analyzed our database of all children referred to our unit over a 10 year period and performed a case note review of all patients with a radiologically proven PLA.

RESULTS

PLA was diagnosed in 15 children (7 boys), 0.5% of all referrals. They presented at a median age of 10 years (range 2 months-15 years). In three children (2 boys), PLA was the first manifestation of chronic granulomatous disease. Among the others, five had radiologic evidence of other intra-abdominal pathology (1 with subsequently proven appendicitis), and four developed portal vein thrombosis with portal hypertension. The commonest isolated pathogen was Staphylococcus aureus. Combined treatment with guided aspiration and prolonged intravenous antibiotics was successful in all patients.

CONCLUSION

PLA is a rare diagnosis in children in the developed world. It may be caused by primary neutrophil disorders even in the absence of a previous history of infection. Co-existent appendicitis, intra-abdominal sepsis, and ascending pylephlebitis must be sought because these children are at risk of developing portal vein obstruction and portal hypertension. Prolonged intravenous antibiotic treatment guided by microbiologic sensitivities is highly effective.

Visceral larva migrans associated with earthworm ingestion: clinical evolution in an adolescent patient

A 16-year-old girl developed a cough, hypereosinophilia (absolute eosinophil count: 32000/mm3), hypergammaglobulinemia, and multiple noncavitary pulmonary nodules 1 month after having ingested an earthworm on a dare. Spirometry revealed moderate restriction and reduced gas diffusion. Parabronchial biopsy demonstrated eosinophilic organizing pneumonitis with multiple eosinophilic microabscesses, and Toxocara titers were elevated (>1:4096). Ophthalmologic examination ruled out ocular larva migrans. The patient received a 10-day course of albendazole (400 mg orally twice daily) and demonstrated significant clinical improvement with resolution of cough and pulmonary function abnormalities. Her white blood cell count and hypergammaglobulinemia normalized within 20 days, yet eosinophils (absolute eosinophil count: 1780/mm3) and Toxocara serologies (>1:4096) remained elevated 3 months after completing antihelminthic therapy. In this instance, the ingested earthworm served as the paratenic carrier of Toxocara larvae from the soil to the patient. This case highlights the clinical evolution of pulmonary visceral larva migrans infection caused by Toxocara spp. associated with a discrete ingestion in an adolescent patient. In addition, it provides a rare opportunity to define the incubation period of visceral larva migrans and emphasizes the importance of education regarding sources of Toxocara infection.

[Hepatic abscesses in childhood: retrospective study about 33 cases observed in New-Caledonia between 1985 and 2003]

Hepatic abscesses in childhood are rarely observed in Europe. The aim of this word was to study how to diagnose and how to treat an hepatic abscess.

METHODS

Between 1985 and 2003, we recensed retrospectively 33 cases of hepatic abscesses hospitalised in the paediatric unit of Noumea.

RESULTS

Children were mainly melanesians (79%), 7 years old on average, having abdominal pains, a clinical and biological infectious syndrome, and abscesses images on ultrasonography or computed tomography. The identified micro-organisms included Entamoeba histolytica in 30% (10 cases); Staphylococcus aureus in 15% (five cases), Staphylococcus coagulase negative in 6% (two cases), Streptococcus D in 3% (one case); Bartonella henselae in 9% (three cases); ascaris in 6% (two cases); Mycobacterium tuberculosis in 6% (two cases). In eight cases no bacteria was identified (24%) but the good evolution after antibiotics and the negative amoebic serology looked like pyogenic abscesses. Two abscesses were aspirated, two were drained, one child had a surgical intervention. There was no death. Following a mean duration of 1 month for antibiotics treatment, outcome was always favourable.

CONCLUSION

Diagnosis of hepatic abscess can be difficult. Ultrasonography shows the abscess but not the causal agent. The amoebic serology is sensible, consequently, its negativity leads to evoke a pyogenic agent. Early antibiotic treatment against pyogenic, anaerobic bacteria, and Entamoeba histolytica is required. Hepatic abscesses in ascaridiosis, tuberculosis and cat-scratch disease are less frequently encountered. If diagnosis remains doubtful or clinical evolution worsens, or if abscess volume increases, a percutaneous aspiration or drainage is needed.

Intestinal nematodes and pulmonary tuberculosis

We report a significantly higher prevalence of intestinal nematodes in patients with pulmonary tuberculosis (TB) compared to a matched control group: 33/57 (57.8%) in patients with TB and 18/86 (20.9%) in the control group; OR = 5.19; 95% CI = 2.33-11.69; p = 0.000). When TB patients eosinophilia was also significantly higher among those with intestinal parasites (69.8%) compared to those without this condition (45.6%). We hypothesized that the immune modulation induced by nematodes is a factor that enhances TB infection/progression and that eosinophilia seen in TB patients is a consequence of helminth infection.

Nematode infections are risk factors for staphylococcal infection in children

Nematode infection may be a risk factor for pyogenic liver abscess in children and we hypothesized that the immunomodulation induced by those parasites would be a risk factor for any staphylococcal infection in children. The present study was designed to compare, within the same hospital, the frequency of intestinal nematodes and Toxocara infection in children with and without staphylococcal infections. From October 1997 to February 1998, 80 children with staphylococcal infection and 110 children with other diseases were submitted to fecal examination, serology for Toxocara sp., evaluation of plasma immunoglobulin levels, and eosinophil counts. Mean age, gender distribution, birthplace, and socioeconomic conditions did not differ significantly between the two groups. Frequency of intestinal nematodes and positive serology for Toxocara, were remarkably higher in children with staphylococcal infections than in the non-staphylococcal group. There was a significant correlation between intestinal nematodes or Toxocara infection and staphylococcal infection in children, reinforced by higher eosinophil counts and higher IgE levels in these children than in the control group. One possible explanation for this association would be the enhancement of bacterial infection by the immunomodulation induced by helminth infections, due to strong activation of the Th2 subset of lymphocytes by antigens from larvae and adult worms.

Pyogenic abscesses and parasitic diseases

Parasitic diseases which during their course in the host switch the immune system from a T helper 1 to a T helper 2 response may be detrimental to the host, contributing to granuloma formation, eosinophilia, hyper-IgE, and increased susceptibility to bacterial and fungal infections. Patients and animals with acute schistosomiasis and hyper-IgE in their serum develop pyogenic liver abscess in the presence of bacteremia caused by Staphylococcus aureus. The Salmonella-S. mansoni association has also been well documented. The association of tropical pyomyositis (pyogenic muscle abscess) and pyogenic liver abscess with Toxocara infection has recently been described in the same context. In tropical countries that may be an interesting explanation for the great morbidity of bacterial diseases. If the association of parasitic infections and pyogenic abscesses and/or fungal diseases are confirmed, there will be a strong case in favor of universal treatment for parasitic diseases to prevent or decrease the morbidity of superinfection with bacteria and fungi.

Human toxocariasis and pyogenic liver abscess: a possible association

OBJECTIVES

To study the role of human toxocariasis in the pathogenesis of pyogenic liver abscess.

METHODS

We compared the serology for toxocariasis and serum levels of IgE in 16 patients with pyogenic liver abscess to those in 32 matched (age and gender) controls to define the possible association between these two entities.

RESULTS

The serology for toxocariasis was positive in 10 of 16 patients compared with 4 of 32 controls. The relative odds and 95% confidence interval (conditional logistic regression), comparing cases and matched controls, was significant (1.4; 95% confidence interval, 1.1-1.7) for Toxocara serology. Regarding IgE serum levels, there was no difference between cases and controls.

CONCLUSIONS

Human toxocariasis can be one of the predisposing causes of pyogenic liver abscess, especially in tropical countries in which this parasitic disease is common. Treatment of human toxocariasis may prevent morbid complications like hepatic abscess and should be considered in patients with clinical and/or serological evidence of Toxocara infection.

Heptaobiliary infections

Although cholangitis is the most prevalent hepatobiliary infectious process, liver abscess represents the most serious and conspicuous hepatobiliary infection. Amebic liver abscess typically occurs in individuals from endemic areas or those traveling to endemic areas. It is associated with an excellent prognosis when managed expediently with antiamebic antibiotics. Recent reports emphasize a possible association between amebic liver abscess and HIV infection. Drainage or surgery for amebic liver abscess is rarely necessary. In contrast, pyogenic liver abscess is associated with significant morbidity and mortality, although the prognosis of patients with this hepatobiliary infection has improved in recent years. Pyogenic liver abscess occurs most often in patients without identifiable predisposing factors, but when identified, they are most often biliary tract-related. Management of pyogenic liver abscess has historically been surgical, but in recent years, there has been a dramatic shift toward noninvasive management, particularly involving strategies based on percutaneous drainage techniques.