ObjectiveTo compare clinical characteristics, etiology, imaging findings, treatment, and in-hospital outcomes between patients with pyogenic liver abscess with and without diabetes to support individualized clinical management.MethodsThis retrospective study included 63 patients diagnosed with pyogenic liver abscess between February 2023 and December 2025 at a tertiary hospital in Xi'an, China. The patients were divided into diabetic and non-diabetic groups. Clinical data, laboratory findings, imaging features, pathogen distribution, treatment, and in-hospital outcomes were compared. Multivariate logistic regression was performed to determine risk factors for percutaneous drainage.ResultsIn total, 63 patients were enrolled; there were no significant differences in sex, age, and inflammatory indicators between the two groups. Alanine transaminase and aspartate transaminase levels were significantly higher in the non-diabetic group, whereas albumin levels were significantly lower in the diabetic group (p = 0.04). The detection rate of Klebsiella pneumoniae was significantly higher in the diabetic group (52.2% vs. 15.0%, p = 0.001). The proportion of patients undergoing puncture and drainage was significantly higher (47.8% vs. 22.5%, p = 0.04) and the length of hospital stay was significantly longer (14.0 (9.0, 17) vs. 10 (9.0, 12.75) days, p = 0.01) in the diabetic group. There was no significant difference in the incidence of sepsis between the two groups. Multivariate regression analysis revealed that K. pneumoniae infection was an independent risk factor for the need for percutaneous drainage (odds ratio = 8.73, 95% confidence interval: 2.36-32.34, p = 0.001).ConclusionDiabetic patients with pyogenic liver abscess characteristically exhibit a predominance of K. pneumoniae infection and a longer hospital stay. Non-diabetic patients present prominent transaminitis and higher Escherichia coli infection rates. K. pneumoniae infection, rather than diabetes itself, is an independent factor associated with drainage requirement in this cohort. Tailored therapeutic strategies are recommended for this patient population based on diabetes status.

Hypervirulent Klebsiella pneumoniae (hvKp) has emerged as a redoubtable global pathogen, distinguished from classical K. pneumoniae (cKp) by its ability to cause life-threatening, community-acquired infections in both healthy and immunocompetent individuals. While its pathogenicity is fundamentally anchored in a specialized virulence arsenal - including the K1/K2 capsular serotypes associated with a hypercapsular structure, the hypermucoviscous phenotype, high-affinity siderophores like aerobactin, and mobile genetic elements such as the KpVP plasmid and ICEKp10 - the true hallmark of hvKp is its sophisticated subversion of the innate cellular immune response. This review synthesizes current evidence on the mechanistic interactions between hvKp and host immune effectors, detailing a cell-by-cell evasion strategy. We highlight how hvKp manipulates neutrophils through the induction of immunosuppressive PD-L1[+]/Siglec-H[+] subpopulations and the strategic delay of apoptosis. Furthermore, we discuss the hijacking of macrophage metabolism, specifically iron and lipid pathways, in addition to inducing dysfunctional M(Kp) macrophage polarization and the formation of the Klebsiella-containing vacuole, which facilitates intracellular survival and replication. Rather than acting as isolated events, we analyze how these cell-specific evasion strategies serve as the foundational chronological checkpoints of pathogenesis. Integrating these mechanisms, we establish an interconnected narrative that culminates in a comprehensive, time-dependent model of pyogenic liver abscess formation, mapping the step-wise progression from portal translocation to host pyroptosis and microabscess consolidation. Finally, we propose that targeting these specific host-pathogen interfaces offers a promising frontier for host-directed therapies.

Pyogenic liver abscess is a potentially life-threatening condition primarily caused by bacterial spread from the gastrointestinal or biliary tract to the liver. As endoscopic retrograde cholangiopancreatography (ERCP) with biliary sphincterotomy becomes more common in the treatment of choledocholithiasis, the risk of developing pyogenic liver abscess increases, with Klebsiella pneumoniae continuing to emerge as a more commonly identified pathogen in North America. Our case describes this unique presentation of a 54-year-old female diagnosed with Klebsiella liver abscess (KLA) following multiple diagnostic and therapeutic interventions: ERCP, biliary sphincterotomy with stent placement, and robot-assisted cholecystectomy. Prophylactic antibiotics, meticulous aseptic techniques during procedures, and close postoperative monitoring are key strategies that may mitigate the risk of KLA. In addition, clinical vigilance for potential bacterial colonization in these high-risk patients may further reduce the incidence of such complications. Importantly, this study highlights the gaps in science and the need for further investigation of endoscopic interventions as potential underlying risk factors associated with pyogenic liver abscess, particularly KLA.

Klebsiella pneumoniae is a common pathogen of pyogenic liver abscess (PLA), particularly among individuals with diabetes mellitus and those of Asian ethnicity. A 32-year-old Filipino man with no prior medical history presented with fever, headache, nausea, and vomiting and was found to have new-onset diabetic ketoacidosis (DKA). Laboratory evaluation revealed leukocytosis, thrombocytopenia, elevated liver enzymes, hyperbilirubinemia and lactic acidosis. Abdominal computed tomography (CT) showed hepatosplenomegaly, variable hepatic abnormalities including < 2 cm hypodense lesions and a large ill-defined area of decreased density in the inferior right liver lobe. The patient was hospitalized for sepsis and DKA. Empiric piperacillin-tazobactam was administered for 24 h and subsequently de-escalated to ceftriaxone after blood cultures grew extended-spectrum β-lactamase-negative Klebsiella pneumoniae; ceftriaxone was continued for 4 weeks. Due to the number, size and inaccessible location of the liver lesions, percutaneous drainage was not feasible. After 16-week follow-up, the patient achieved complete clinical recovery and radiological resolution of hepatic lesions. This case highlights variable hepatic lesion presentations in Klebsiella liver abscess (KLA) with successful conservative management without drainage.

Gas-forming pyogenic liver abscess (GFPLA) is a rare and highly fatal subtype of bacterial liver abscess, closely related to diabetes and hypervirulent Klebsiella pneumoniae infection. This case series analyzed seven patients diagnosed with GFPLA by CT, aiming to explore their clinical characteristics and prognosis. Among the patients, four died, with a total mortality rate of 57.1%, significantly higher than the 27.7%-37.1% reported in the literature. The sequential organ failure assessment (SOFA) scores of the deceased patients at admission were all ≥7, suggesting a potential association between higher SOFA scores and mortality in this small series. The pathogen analysis showed that 85.7% of the cases were hypervirulent Klebsiella pneumoniae infections that were positive in the latex agglutination test, and the strains were generally resistant to ampicillin but sensitive to carbapenems and enzyme-inhibitor combination preparations. In terms of treatment, only a few patients received puncture drainage, and some were unable to implement it due to coagulation dysfunction or small abscess volumes. These findings highlight the need for early identification and close monitoring of SOFA scores in patients with GFPLA, particularly those with diabetes, and suggest that a multidisciplinary approach, including effective antibiotics (e.g., carbapenems), active blood glucose control, and timely drainage, may be important for improving outcomes. However, due to the small sample size and exploratory nature of this study, observed associations should be interpreted with caution and require validation in larger cohorts.

Pyogenic liver abscess (PLA) is one of the most common and severe infectious diseases encountered in clinical practice. It is characterized by rapid progression, and failure to recognize and treat the condition promptly may readily result in septic shock and multiple organ dysfunction syndrome (MODS), thereby posing a serious threat to the patient's life. However, clinical research focusing on the development of MODS in patients with liver abscess remains limited. Therefore, this study aimed to develop and validate a predictive model for MODS in patients with PLA, identify associated risk factors and clinical characteristics, and facilitate the identification of high-risk patients at admission and during the early stage of hospitalization, thereby supporting timely clinical decision-making and management.

Anorectal mucosal melanoma is a rare and aggressive malignancy that is often diagnosed after regional or distant spread. Liver lesions in patients with melanoma are usually approached with metastatic disease in mind; however, extensive necrosis can make metastases appear clinically and radiologically similar to pyogenic abscesses. We report a 76-year-old woman with a history of anorectal mucosal melanoma treated by abdominoperineal resection with microscopically negative (R0) margins and adjuvant radiotherapy 10 years earlier. She presented with right upper quadrant pain, elevated inflammatory markers, and ultrasound findings interpreted as a hepatic abscess. Empirical broad-spectrum antibiotics and computed tomography (CT)-guided drainage yielded sterile brown hemorrhagic fluid. Persistent symptoms, fever, black-pigmented catheter output, sterile cultures, and magnetic resonance imaging (MRI) showing a centrally necrotic lesion prompted multidisciplinary reassessment. Cytology demonstrated melanin pigment but no viable malignant cells. The patient underwent right hemihepatectomy with cholecystectomy. Histopathology confirmed metastatic melanoma with approximately 95% tumor necrosis and scattered viable cells positive for SRY-box transcription factor 10 (SOX10) and human melanoma black 45 (HMB-45). This case emphasizes that necrotic melanoma metastasis can masquerade as a liver abscess and that sterile cultures, pigmented drainage, prior melanoma history, and discordant imaging should prompt early oncologic reassessment and tissue confirmation.