Abdullah Hafeez, MD1, Omar Alkasabrah, MD1, Faiza Jajja, MD1, Rohullah Rasikh, MD1, Hamza Ansari, MD2, M Housam Nanah, MD3, Lisa kop, MD1, Tanuj Sharma, MD1 1Landmark Medical Center, Woonsocket, RI; 2NYMC St. Mary's and St. Clare, Denville, NJ; 3Cleveland Clinic, Cleveland, OH Introduction: A 37-year-old male with prior diverticulitis and intra-abdominal abscess (2021) presented with three months of fatigue, right upper quadrant pain, weight loss, and anorexia. Exam revealed hepatomegaly and diminished right lung base sounds. Labs showed sodium 128 mEq/L, bilirubin 1.9 mg/dL, AST 70 U/L, and lactate 4.4 mmol/L.
CT revealed a 20.2 cm multiloculated hypodense liver mass with adjacent sigmoid colon thickening. Differential included diverticulitis-related abscess versus malignancy. CT-guided drainage yielded 1600 mL of purulent fluid; cultures grew Fusobacterium and Peptostreptococcus anaerobius. The patient improved on IV piperacillin-tazobactam, followed by outpatient ertapenem. He was referred for colonoscopy and tumor marker evaluation (CEA).
Case Description/
Methods: Fusobacterium and Peptostreptococcus are gut commensals that may translocate to the liver via the portal system after mucosal disruption. Though typically seen in immunocompromised patients, anaerobic PLAs can occur in immunocompetent individuals, especially those with diverticular disease.
Prompt imaging, percutaneous drainage, and anaerobe-directed antibiotics are essential. Empiric therapy includes beta-lactam/beta-lactamase inhibitors, cephalosporins with metronidazole, or carbapenems. This case highlights the importance of early recognition, tailored antimicrobial therapy, and evaluation for underlying colonic pathology to prevent recurrence. Discussion: Anaerobic PLAs are uncommon but clinically significant. Fusobacterium and Peptostreptococcus, commensals of the gut and oral cavity, may access the liver through the portal system following mucosal disruption. Although most anaerobic PLAs occur in immunocompromised patients, this case underscores their relevance in immunocompetent hosts with predisposing gastrointestinal pathology.
Diagnosis is often delayed due to nonspecific symptoms and culture challenges. Prompt imaging, drainage, and anaerobe-directed antibiotics are critical. This patient’s size of abscess warranted percutaneous drainage, followed by a 6-week antibiotic course. Empiric regimens include beta-lactam/beta-lactamase inhibitors, third-generation cephalosporins with metronidazole, or carbapenems.
This case emphasizes early recognition and aggressive management of anaerobic PLAs, especially in those with diverticular disease. It also reinforces the need for further investigation into potential underlying malignancy, as colonic neoplasia may serve as a nidus for such infections.
Disclosures: Abdullah Hafeez indicated no relevant financial relationships. Omar Alkasabrah indicated no relevant financial relationships. Faiza Jajja indicated no relevant financial relationships. Rohullah Rasikh indicated no relevant financial relationships. Hamza Ansari indicated no relevant financial relationships. M Housam Nanah indicated no relevant financial relationships. Lisa kop indicated no relevant financial relationships. Tanuj Sharma indicated no relevant financial relationships.
Abdullah Hafeez, MD1, Omar Alkasabrah, MD1, Faiza Jajja, MD1, Rohullah Rasikh, MD1, Hamza Ansari, MD2, M Housam Nanah, MD3, Lisa kop, MD1, Tanuj Sharma, MD1. P3823 - Silent Invaders: Anaerobic Pyogenic Liver Abscess in Complicated Diverticulitis, ACG 2025 Annual Scientific Meeting Abstracts. Phoenix, AZ: American College of Gastroenterology.
