Case Presentation: A 56-year-old male with a history of 45 pack-year smoking, peptic ulcer, and cholecystectomy 5 months ago presented with worsening epigastric pain and 70-pound weight loss over the last 3 months, associated with subjective fevers, drenching night sweat, and malaise. The patient was hospitalized a month ago for the same reason, when computed tomography (CT) found a pancreatic head and two 4cm liver masses. Biopsy of the pancreatic mass showed nonspecific atypical cells and he was discharged home with a follow up plan for suspected metastatic pancreatic carcinoma. Progressive malaise and weight loss however prompted him to the second presentation. On presentation, he was afebrile but tachycardic to 120 bpm and tachypneic to 31 per minute. His physical exam was notable for poorly localized right-sided abdominal tenderness. Laboratory tests showed white blood cell 11,400 /μL, normal liver enzymes, lipase 22 U/L, lactic acid 1.2 mmol/L, and C-reactive protein 20.9 mg/dL. Piperacillin/Tazobactam was started as he met SIRS criteria. Contrast CT demonstrated a 17cm liver mass which enlarged from 4 cm and became confluent in 1 month with a smaller pancreatic head mass. Contrast magnetic resonance imaging (MRI) demonstrated loculated rim-enhancing hepatic collection compatible with intrahepatic abscess. Interventional radiology placed a percutaneous drain on the day 5. Its abscess culture grew Streptococcus Constellatus. The growth was too low to perform susceptibilities. Antibiotics were de-escalated to Ceftriaxone and Metronidazole and the patient was discharged with a peripherally inserted central catheter line on the day 11. After discharge, another drain was placed for persistent liver abscess. Follow up CT after 4 weeks confirmed the resolution of abscess and two drains were removed.
Discussion: Pyogenic liver abscess (PLA) is an uncommon but fatal disease if left untreated, with a frequency of 20 per 100,000 admissions in the Western world. Streptococcus Constellatus, part of Streptococcus Milleri group, has been reported as the causative organism. PLA in this case potentially occurred as delayed ascending infection following laparoscopic cholecystectomy 5 months ago as PLA that occurred 9 months after intraabdominal surgery has been reported in the past. This patient presented with non-specific symptoms which mimicked malignancy. Moreover, he never became febrile and his initial CT showed a pancreatic head mass with 2 hepatic lesions, which anchored clinicians’ mind to cancer diagnosis at first. Drastic changes in size of masses questioned its diagnosis. Contrast MRI is a more reliable diagnostic imaging modality than CT or ultrasound to differentiate liver abscess from tumors.
Conclusions: PLA can mimic hepatic malignancy in which case early diagnosis can be challenging. Careful history taking and early suspicion of PLA may help determine the need for further diagnostic workup including MRI and/or percutaneous drainage.