Clinical management, pathogen spectrum and outcomes in patients with pyogenic liver abscess in a German tertiary-care hospital.

Pyogenic liver abscesses (PLA) are life-threatening disorders and require immediate treatment, but structured evidence is sparse and treatment guidelines are not established. In a retrospective observational study of 221 adult PLA patients (mean age 63 years, 63% men) treated between 2013 and 2019 at the Leipzig University Medical Center, we characterized pathogen spectrum, clinical management and outcomes. Biliary malignancies (33%), cholelithiasis (23%) and ischemic biliary tract disease (16%) were most common causes of PLA. Comorbidities included malignancies (40%) and diabetes mellitus (35%). Abdominal ultrasound was the preferred initial imaging modality (58%). Enterobacterales (58%), enterococci (42%) and streptococci (18%) were identified as most frequent pathogens. 97% of patients were treated with antibiotics and 75% of patients underwent an invasive treatment procedure. The 30-day mortality was almost identical in patients with and without underlying malignancy (14.6% vs. 14.4%, p = 0.96), while the one-year outcome differed significantly (58.4% vs. 29.6%, p < 0.001). Positive blood cultures (OR 4.78, 95% CI 1.39 to 22.5, p = 0.023) and detection of Enterobacterales (OR 3.55, 95% CI 1.40 to 9.97, p = 0.010) were associated with increased 30-day-mortality. We conclude that ultrasound, extensive microbiologic diagnosis, adequate anti-infective therapy and early intervention are crucial for the management of PLA.

Clinical features and risk factors for pyogenic liver abscess caused by multidrug-resistant organisms: A retrospective study.

The incidence rate of pyogenic liver abscess caused by multidrug-resistant bacteria has increased in recent years. This study aimed to identify the clinical characteristics and risk factors for pyogenic liver abscess caused by multidrug-resistant bacteria. We conducted a retrospective analysis of the clinical features, laboratory test results, and causes of pyogenic liver abscesses in 239 patients admitted to a tertiary hospital. Multivariable logistic regression was used to identify risk factors for multidrug resistance. Among patients with pyogenic liver abscesses, the rate of infection caused by multidrug-resistant organisms was observed to be 23.0% (55/239), with a polymicrobial infection rate of 14.6% (35/239). Additionally, 71 cases (29.7%) were associated with biliary tract disease. Patients with pyogenic liver abscesses caused by multidrug-resistant organisms had a significantly higher likelihood of polymicrobial infection and increased mortality (7/44 [15.9%] vs. 3/131 [2.3%]; p = .003). The Charlson Comorbidity Index (adjusted odds ratio [aOR]: 1.32, 95% confidence interval [CI]: 1.06-1.68), hospitalization (aOR: 10.34, 95% CI: 1.86-60.3) or an invasive procedure (aOR: 9.62; 95% CI: 1.66-71.7) within the past 6 months, and gas in the liver on imaging (aOR: 26.0; 95% CI: 3.29-261.3) were independent risk factors for pyogenic liver abscess caused by multidrug-resistant bacteria. A nomogram was constructed based on the risk factors identified. The nomogram showed high diagnostic accuracy (specificity, 0.878; sensitivity 0.940). Multidrug-resistant organisms causing pyogenic liver abscesses have specific characteristics. Early identification of patients at high risk of infection with multidrug-resistant organisms could help improve their management and enable personalized treatment.

Clinical characteristics of pyogenic liver abscess with and without biliary surgery history: a retrospective single-center experience.

BACKGROUND & AIMS: Pyogenic liver abscess (PLA) is a common hepatobiliary infection that has been shown to have an increasing incidence, with biliary surgery being identified as a trigger. Our aim was to investigate the clinical characteristics and treatments of PLA patients with and without a history of biliary surgery (BS). METHODS: The study included a total of 353 patients with PLA who received treatment at our hospital between January 2014 and February 2023. These patients were categorized into two groups: the BS group (n = 91) and the non-BS group (n = 262). In the BS group, according to the anastomosis method, they were further divided into bilioenteric anastomoses group (BEA, n = 22) and non-bilioenteric anastomoses group (non-BEA, n = 69). Clinical characteristics were recorded and analyzed. RESULTS: The percentage of PLA patients with BS history was 25.78%. The BS group exhibited elevated levels of TBIL and activated APTT abnormalities (P = 0.009 and P = 0.041, respectively). Within the BS group, the BEA subgroup had a higher prevalence of diabetes mellitus (P < 0.001) and solitary abscesses (P = 0.008) compared to the non-BEA subgroup. Escherichia coli was more frequently detected in the BS group, as evidenced by positive pus cultures (P = 0.021). The BS group exhibited reduced treatment efficacy compared to those non-BS history (P = 0.020). Intriguingly, the BS group received a higher proportion of conservative treatment (45.05% vs. 21.76%), along with reduced utilization of surgical drainage (6.59% vs. 16.41%). CONCLUSIONS: Patients with BS history, especially those who have undergone BEA, have an increased susceptibility to PLA formation without affecting prognosis.

Pyogenic liver abscess presenting as fatal fulminant acute liver failure - a case report.

Liver abscess causing and presenting as acute liver failure is rare; it does not result in hepatitis as it causes focal hepatic necrosis. With drainage of pus, recovery is the rule. However, a child having multiple abscesses may present with acute fulminant liver failure.

Paeniclostridium sordellii causing liver abscess: A rare case report in India.

Paeniclostridium sordellii, an anaerobic bacterium, causes hepatic infections in alcoholics and post-surgery (liver transplantation). While liver and brain abscesses are rare, drainage procedures and targeted antibiotic therapy assisted by early microbiological diagnosis have reduced mortality rates. We report a rare case of pyogenic liver abscess caused by Paeniclostridium sordellii in India, the early diagnosis of which has led to life saving outcome for the patient. Hence, the microbiological diagnosis and comprehensive medical-surgical treatment are vital for preventing mortality in Paeniclostridium sordellii infections.

A challenging case of carbapenem resistant Klebsiella pneumoniae-related pyogenic liver abscess with capsular polysaccharide hyperproduction: a case report.

BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKP) infections are a major public health problem, necessitating the administration of polymyxin E (colistin) as a last-line antibiotic. Meanwhile, the mortality rate associated with colistin-resistant K. pneumoniae infections is seriously increasing. On the other hand, importance of administration of carbapenems in promoting colistin resistance in K. pneumoniae is unknown. CASE PRESENTATION: We report a case of K. pneumoniae-related pyogenic liver abscess in which susceptible K. pneumoniae transformed into carbapenem- and colistin-resistant K. pneumoniae during treatment with imipenem. The case of pyogenic liver abscess was a 50-year-old man with diabetes and liver transplant who was admitted to Abu Ali Sina Hospital in Shiraz. The K. pneumoniae isolate responsible for community-acquired pyogenic liver abscess was isolated and identified. The K. pneumoniae isolate was sensitive to all tested antibiotics except ampicillin in the antimicrobial susceptibility test and was identified as a non-K1/K2 classical K. pneumoniae (cKp) strain. Multilocus sequence typing (MLST) identified the isolate as sequence type 54 (ST54). Based on the patient's request, he was discharged to continue treatment at another center. After two months, he was readmitted due to fever and progressive constitutional symptoms. During treatment with imipenem, the strain acquired blaOXA-48 and showed resistance to carbapenems and was identified as a multidrug resistant (MDR) strain. The minimum inhibitory concentration (MIC) test for colistin was performed by broth microdilution method and the strain was sensitive to colistin (MIC < 2 µg/mL). Meanwhile, on blood agar, the colonies had a sticky consistency and adhered to the culture medium (sticky mucoviscous colonies). Quantitative real-time PCR and biofilm formation assay revealed that the CRKP strain increased capsule wzi gene expression and produced slime in response to imipenem. Finally, K. pneumoniae-related pyogenic liver abscess with resistance to a wide range of antibiotics, including the last-line antibiotics colistin and tigecycline, led to sepsis and death. CONCLUSIONS: Based on this information, can we have a theoretical hypothesis that imipenem is a promoter of resistance to carbapenems and colistin in K. pneumoniae? This needs more attention.

Cryptogenic pyogenic liver abscess caused by Fusobacterium necrophorum in an immunocompetent patient.

Pyogenic liver abscesses are potentially fatal conditions that require prompt treatment with drainage and appropriate antimicrobial therapy. Fusobacterium necrophorum is a gram-negative rod that is found in the oral cavity, gastrointestinal tract and female genital tract. It is an extremely rare cause of liver abscess, particularly in the absence of risk factors or exposures. We describe an unusual case of a cryptogenic F. necrophorum hepatic abscess without a clear source despite extensive investigation in a young, immunocompetent patient without known risk factors or exposures for such an infection.

Liver abscess due to Granulicatella adiacens in an immunocompetent patient: Case report. / Absceso hepático por Granulicatella adiacens

Pyogenic liver abscesses due to Granulicatella adiacens are infections associated with high mortality, mainly in immunocompromised patients. The main microorganisms associated with liver abscesses are Klebsiella pneumoniae, and Escherichia coli, though it may also be polymicrobial. However, case reports describing liver infection by Granulicatella adiacens are scarce. We present the case of an immunocompetent adult patient who presented 15 days of evolution consisting of quantified fever peaks associated with asthenia, adynamia, chills, jaundice and coluria. The initial clinical examination revealed a generalized icteric tint without abdominal pain, and blood pressure with a tendency to hypotension. Biliopancreatic confluent neoplasia, secondary cholangitis and sepsis of biliary origin were suspected, initiating fluid resuscitation and antibiotic therapy; blood cultures and complementary diagnostic studies were taken. Hepatobiliary ultrasound with evidence of an abscess of 73 x 62 mm in segment IV; the bile duct and pancreas were within normal limits. To better characterize the lesion evidenced in the liver, a contrast-enhanced computed tomography of the abdomen was performed. The patient completed antibiotic management with ciprofloxacin, vancomycin, and metronidazole in good condition and was successfully discharged. This is the first pyogenic liver abscess reported caused by Granulicatella adiacens in an immunocompetent patient, in whom early microbiological diagnosis in conjunction with targeted antibiotic treatment and percutaneous drainage of the lesion was decisive in the clinical outcome.

Los abscesos hepáticos piógenos por Granulicatella adiacens son infecciones asociadas a una alta mortalidad, principalmente en pacientes inmunocomprometidos. Los principales microorganismos asociados a los abscesos hepáticos son Klebsiella pneumoniae y Escherichia coli, aunque pueden ser polimicrobianos. Sin embargo, los informes de casos que describen la infección hepática por G. adiacens son muy escasos. Se presenta el caso de un paciente adulto inmunocompetente que presentó 15 días de evolución de picos febriles cuantificados asociados a astenia, adinamia, escalofríos, ictericia y coluria. El examen clínico inicial reveló un tinte ictérico generalizado sin dolor abdominal, y presión arterial con tendencia a la hipotensión. Se sospechó neoplasia biliopancreática confluente, colangitis secundaria y sepsis de origen biliar, y se inició reanimación con líquidos y antibioterapia. Se tomaron hemocultivos y estudios diagnósticos complementarios. En el ultrasonido hepatobiliar, se observó un absceso de 73 x 62 mm en el segmento IV; la vía biliar y el páncreas se encontraron dentro de los límites normales. Se realizaron múltiples pruebas moleculares de detección de microorganismos (FilmArray), y se identificó a G. adiacens como el principal agente patógeno. El paciente completó el manejo antibiótico con ciprofloxacina, vancomicina y metronidazol en buenas condiciones y fue dado de alta con éxito. Este es el primer absceso hepático piógeno reportado causado por G. adiacens en un paciente inmunocompetente, en quien el diagnóstico microbiológico temprano en conjunto con el tratamiento antibiótico dirigido y el drenaje percutáneo de la lesión fueron determinantes en el resultado clínico.

Occult colon cancer with liver abscess and pancreatitis as the first manifestations: A case report.

INTRODUCTION: Klebsiella pneumoniae-induced liver abscess (KP-PLA) is a common type of pyogenic liver abscess, severe acute pancreatitis (SAP) has high mortality, and poor prognosis in advanced colon cancer. There have been no report of SAP complicated with colon cancer after KP-PLA as so far. In this study, we reported a case of SAP secondary to KP-PLA with colon cancer for the first time, so as to provide reference for clinical diagnosis and treatment of these diseases. PATIENT CONCERNS AND DIAGNOSIS: A 64-year-old woman with a history of diabetes visited our hospital with abdominal pain for 5 + days. He was diagnosed with KP-PLA a month ago, which had not healed when he was admitted. He was diagnosed with SAP, and histological examination of colonic biopsy confirmed the diagnosis of moderately differentiated adenocarcinoma. INTERVENTIONS AND OUTCOMES: He was treated with intravenous antibiotics and underwent modified endoscopic mucosal resection under colonoscopy. We conducted a 2-month follow-up, and there was no recurrence of liver abscess and pancreatitis. CONCLUSION: Screening for intestinal tumors is necessary in patients with cryptogenic liver abscess, especially KP-PLA with diabetes.

Pyogenic liver abscess in non-liver cancer patients and liver cancer patients treated with TACE: Etiological characteristics, treatment, and outcome analysis.

Clinical, laboratory, and microbiological features, clinical outcomes, and pyogenic liver abscess (PLA) prognosis evaluation in non-liver cancer (Non-LC) and liver cancer patients treated with transarterial chemoembolization (TACE, LC-TACE). Clinical data of 48 consecutive PLA patients from January 2016 to December 2020 were retrospectively analyzed. Mortality between two PLA patient groups were compared, and mortality risk factors were evaluated. A total of 48 PLA patients (31 males and 17 females) from January 2016 to December 2020 met the study's inclusion criteria. There were 32 and 16 patients in the Non-LC and LC-TACE groups, respectively. Positive pus culture rate in the Non-LC group was 87.5% and positive pus culture rate in LC-TACE group was 81.3%. In the Non-LC group, 28 patients improved after treatment, 1 patient did not improve, and 3 patients died during hospitalization, with a 9.4% mortality rate. In the LC-TACE group, nine patients improved after treatment, three patients did not improve, and four patients died during hospitalization, with a 25% mortality rate. The Non-LC group cure time was 37.4 ± 23.1 days, while the LC-TACE group was 91.5 ± 49.7 days. PLA of the Non-LC group and the LC-TACE group were different in terms of pathogenic bacteria and cure time, and so on. A more comprehensive treatment should be considered for PLA after TACE.

Emergence of K1 ST23 and K2 ST65 hypervirulent klebsiella pneumoniae as true pathogens with specific virulence genes in cryptogenic pyogenic liver abscesses Shiraz Iran.

Hypervirulent Klebsiella pneumoniae (hvKp) pathotype is emerging worldwide in pyogenic liver abscesses (PLAs). However, the role of virulence factors in pathogenicity remains unclear. On the other hand, the epidemiology of PLAs in Iran is unknown. From July 2020 to April 2022, bacterial species were isolated and identified from the drainage samples of 54 patients with PLAs. K. pneumoniae as the most common pathogen of pyogenic liver abscesses was identified in 20 (37%) of the 54 patients. We analyzed the clinical and microbiological characteristics of K. pneumoniae-related pyogenic liver abscesses. Antibiotic susceptibility testes and string test were performed. 16S rRNA, antibiotic resistance, and virulence genes were determined by polymerase chain reaction amplification. Clonal relatedness of isolates was identified by multilocus sequence typing. Virulence levels were assessed in the Galleria mellonella larval infection model. Four hvKp isolates (K1/K2) were found to be responsible for cryptogenic PLAs, and 16 classical K. pneumoniae isolates (non-K1/K2) were associated with non-cryptogenic PLAs. Three capsular serotype K1 strains belonged to sequence type 23 (ST23) and one K2 strain to ST65. Meanwhile, the non-K1/K2 strains belonged to other STs. ST231 was the most common strain among the classical K. pneumoniae strains. Compared with the non-K1/K2 strains, capsular serotypes K1/K2 strains were less resistant to antibiotics, had positive string test results, and had more virulence genes. In Galleria mellonella, a concentration of 106 colony-forming units of the K1 hvKp strain resulted in 100% death at 24 hours, confirming the higher virulence of the hvKp strain compared with cKp. K. pneumoniae isolates represented that the acquisition of any plasmid or chromosomal virulence genes contributes to pathogenicity and high prevalence in PLAs. Meanwhile, hvKp isolates with a specific genetic background were detected in cryptogenic PLAs.

Characteristics of Pyogenic Liver Abscess: Experience of a single centre in Oman.

Objectives: This study aimed to analyse the epidemiological, aetiological and clinical characteristics of pyogenic liver abscess (PLA) occurring in Oman. The intention was to obtain the information needed for the adequate liver abscess (LA) empirical treatment. LA can develop as a complication of hepatobiliary disease or other intraabdominal infections, but more recently, it is associated with primary and secondary liver malignancies and their treatment. Methods: This retrospective study took place in the Royal Hospital, Muscat, Oman. Consecutive patients treated for LA from January 2013 to December 2017 were enrolled. Their demographic and clinical data were used to study the characteristics of PLA occurring in Oman. Results: A total of 53 patients with PLA were enrolled in the study. They were predominantly male and younger than 60 years. Klebsiella pneumoniae was found to be the most common bacteria causing LA. Clinical presentation was non-specific, and abdominal pain and high fever were the most common symptoms. Conclusion: The majority of PLAs are caused by K. pneumoniae, so the empirical treatment should begin with antibiotic directed against it. Further studies are needed to establish the local role of anaerobic bacteria in PLA and monitor the presence of hypervirulent K. pneumoniae in Oman.

Clinical Characteristics of Diabetes Complicated by Bacterial Liver Abscess and Nondiabetes-Associated Liver Abscess.

Background: Bacterial liver abscess (BLA) is a secondary infectious disease caused by hepatic parenchymal inflammation and bacterial necrosis. Studies have shown that diabetic patients with BLA have higher rates of related adverse events than patients without diabetes. Aim: To explore the clinical characteristics of BLA complicated with diabetes and nondiabetes-related BLA. Methods: From January 2019 to June 2020, 61 diabetic patients with BLA were included as the study group, and 61 BLA patients without diabetes were included as the control group. Clinical manifestations, laboratory examination index (prothrombin activity (PTA), albumin (propagated), white blood cell count (WBC), red blood cell count (RBC), plasma fibrinogen (FIB), C-reactive protein (CRP), neutrophil percentage (NEUT), and prealbumin (PA)) levels, blood cultivation, and fester situation in the two groups were analyzed. Results: No differences of Fever, right upper abdominal pain, jaundice, vomiting and nausea, liver tenderness, and liver pain upon percussion were observed between the study and control groups. However, chill, cough and expectoration, and liver pain upon percussion were higher in the study group, while abdominal distension was lower. WBC, RBC, PA, PTA, FIB, and CRP were higher than the control group. NEUT was higher in the study group than in the control group and Alb was lower than that in the control group. There was no significant difference between the positivity of blood bacterial culture in the study and control groups. The positivity rate of Klebsiella pneumoniae in Gram-negative aerobic bacteria in the study group was higher than that in the control group. There was no significant difference between the positivity of fester culture of the two groups. The positivity of K. pneumoniae in Gram-negative aerobic bacteria in the study group was higher than that in the control group. The positivity of E. coli was lower in the study group than in the control group. Conclusion: Clinical manifestations and laboratory results of BLA patients with and without diabetes mellitus were significantly different. The symptoms of diabetics with BLA were serious.

Anaerobe coverage is important for the prognosis of pyogenic liver abscess: A population-based study in Korea.

BACKGROUND: Gram-negative bacteria such as Klebsiella pneumoniae and Escherichia coli are the most common cause of pyogenic liver abscess (PLA). We investigated whether the use of anaerobic-covering antibiotics is essential for the treatment of pyogenic liver abscess. METHODS: We analyzed the Health Insurance Review and Assessment Service data in Korea between 2007 and 2017. We classified PLA into two groups: a group using antibiotics that inhibited only aerobic strains (anaerobe (-) group) and a group using antibiotics that inhibited both aerobic and anaerobic strains (anaerobe (+) group). The primary outcome was the difference in in-hospital mortality between the two groups. RESULTS: During this period, a total of 30,690 PLA patients were obtained. There were 6733 patients in the anaerobe (-) group and 23,957 patients in the anaerobe (+) group. In-hospital mortality was significantly lower in the anaerobe (+) group than the anaerobe (-) group (7.9% vs. 15.6%, p < 0.001). In multivariate analysis, the use of anaerobic antibiotics reduced the in-hospital mortality by 42% (odds ratio 0.42, 95% confidence interval 0.38-0.46, p < 0.001) after adjusting for age and comorbidities. Furthermore, the improvement of in-hospital mortality was present regardless of the presence of cancer or diabetes. CONCLUSION: The use of broad-spectrum empirical antibiotics covering anaerobic strains is important for the treatment of pyogenic liver abscess.

Genetic Diversity and Pathogenic Features in Klebsiella pneumoniae Isolates from Patients with Pyogenic Liver Abscess and Pneumonia.

While Klebsiella pneumoniae is a common cause of nosocomial and community-acquired infections, including pneumonia and pyogenic liver abscess, little is known about the population structure of this bacterium. In this study, we investigated the prevalence and molecular characteristics of K. pneumoniae isolates from carriers, pyogenic liver abscess patients, and pneumonia patients, and genomic and phenotypic assays were used to determine the differences among the isolates. A total of 232 K. pneumoniae isolates were subtyped into 74 sequence types (STs). The isolates from different sources had their own STs, and the predominant subtypes in liver abscess and pneumonia patients were ST23 and ST11, respectively. Pangenome analysis also distinguished three phylogroups that were consistent with the isolate sources. The isolates collected from liver abscess patients carried significantly more virulence factors, and those from pneumonia patients harbored significantly more resistance genes and replicons. Almost all isolate STs (93/97 [95.88%]) from liver abscesses strongly correlated with the virulence factor salmochelin, while most pneumonia isolate STs (52/53 [98.11%]) from pneumonia did not correlate with salmochelin. The isolates collected from liver abscesses showed higher virulence in the cytotoxicity and mouse models. These data provide genomic support for the proposal that isolates collected from carriers, liver abscess patients, and pneumonia patients have distinct genomic features. Isolates from the different sources are largely nonoverlapping, suggesting that different patients may be infected via different sources. Further studies on the pathogenic mechanisms of salmochelin and other virulence factors will be required. IMPORTANCE While Klebsiella pneumoniae is a common cause of nosocomial and community-acquired infections, including pneumonia and pyogenic liver abscess, little is known about the population structure of this bacterium. We collected 232 isolates from carriers, pyogenic liver abscess patients, and pneumonia patients, and the isolates from different sources had their own sequence types. Pangenome analysis also distinguished three phylogroups that were consistent with the isolate sources. The isolates collected from liver abscess patients carried significantly more virulence factors, and those from pneumonia patients harbored significantly more resistance genes and replicons. Besides, there was a strong link between salmochelin and liver abscess. The isolates collected from liver abscesses also showed higher virulence in the cytotoxicity and mouse models. Isolates collected from different sources have distinct genomic features, suggesting that different patients may be infected via different sources.

Clinical characteristics and outcome of patients with enterococcal liver abscess.

Epidemiology of bacteria isolated from pyogenic liver abscesses change, and an increase in enterococci has been reported in European hospitals. The aim of this study was to investigate the clinical characteristics and outcome of enterococcal PLA. We performed a retrospective analysis of patients with microbiologically confirmed PLA at three German university centers. Indicators of enterococcal PLA were determined using binary logistic regression, and survival analysis was performed using Kaplan-Meier statistics and Cox regression analysis. Enterococci were isolated in 51/133 (38%) patients with PLA. Patients with enterococcal PLA had smaller abscess diameter (4.8 vs. 6.7 cm, p = 0.03) than patients with non-enterococcal PLA, but had more frequent polymicrobial culture results. In univariate logistic regression analysis, alcohol abuse (OR 3.94, 95% CI 1.24-12.49, p = 0.02), hepatobiliary malignancies (OR 3.90, 95% CI 1.86-8.18, p < 0.001) and cirrhosis (OR 6.36, 95% CI 1.27-31.96, p = 0.02) were associated with enterococcal PLA. Patients with enterococcal PLA had a higher mortality than patients with non-enterococcal PLA (hazard ratio 2.92; 95% confidence interval 1.09-7.80; p = 0.03), which remained elevated even after excluding patients with hepatobiliary malignancies, cirrhosis, and transplant recipients in a sensitivity analysis. The increased mortality was associated with non-fecal enterococci but not in patients with Enterococcus faecalis. In this retrospective, multicenter study, enterococcal PLA was common and indicated an increased risk of mortality, underscoring the need for close clinical monitoring and appropriate treatment protocols in these patients.

Spontaneous rupture of pyogenic liver abscess with subcapsular hemorrhage mimicking ruptured hepatocellular carcinoma: A case report.

RATIONALE: Spontaneous rupture of PLA (pyogenic liver abscess) is an extremely rare and life-threatening event. Ruptured PLA is very difficult to distinguish from malignant HCC (hepatocellular cancer) rupture or cholangiocarcinoma rupture on CT (computed tomography) scan. PATIENT CONCERNS: We describe the case of a 71-year-old man with fever, right upper abdominal pain, nausea with intermittent vomiting, and general fatigue. He had no medical or surgical history. DIAGNOSIS: CT scan showed a hypodense mass in right hepatic lobe and MRI (magnetic resonance imaging) revealed a heterogenous mass of ∼6 cm in segment VI of the liver and heterogenous fluid in the subcapsular region. We made a tentative diagnosis of HCC rupture with subcapsular hemorrhage based on these findings. INTERVENTION: After improving the patient's condition by administering empirical therapy consisting of intravenous antibiotics and fluids, we performed surgical exploration. Gross examination of the abdomen showed that almost the entire right hepatic lobe was hemorrhagic and affected by peritonitis. Therefore, we performed right hepatectomy. The intraoperative frozen biopsy revealed suspicious PLA with marked necrosis, neutrophil infiltration, and hemorrhagic rupture, although no malignant tissue or fungus was observed. The postoperative secondary pathology report confirmed the diagnosis of PLA with hemorrhagic rupture. OUTCOMES: The patient was discharged 13 days after the operation. Follow-up CT was performed 5 months after discharge and revealed no abnormal findings. LESSONS: A high index of suspicion is key to preventing misdiagnosis of ruptured PLA and improving prognosis. Furthermore, even if rupture of the PLA is initially localized, delayed peritonitis may occur during medical treatment. Therefore, vigilant monitoring is essential.

Fusobacterium nucleatum causing a pyogenic liver abscess: a rare complication of periodontal disease that occurred during the COVID-19 pandemic.

Fusobacterium nucleatum is a periodontal commensal and pathogen. In rare cases, these anaerobic gram-negative bacilli have been reported to cause pyogenic liver abscesses (PLAs). We describe a patient who developed a periodontal abscess during the COVID-19 pandemic and was unable to access the restricted General Dental Services at this time. She subsequently developed a F. nucleatum bacteraemia and liver abscess. The non-specific signs and symptoms experienced meant the patient self-isolated due to suspected COVID-19 infection and presentation to hospital was delayed. We also include the results of a literature search of other cases of PLAs attributed to F. nucleatum PLAs often develop insidiously. They require percutaneous drainage and prolonged antimicrobial therapy. Clinicians should be aware of this rare complication of a dentoalveolar infection in a patient who is systemically unwell.