Hepatic Mass
Written by: Dr. Rita Kumar
Edited by: Dr. Joann Hsu
The case:
50 year old Asian man with PMHx of DM and HLD presented to the ED as a sepsis activation. He presented from home complaining of a fever for 10 days associated with nausea and cough. However, he denied abdominal pain, vomiting, nasal congestion, chest pain or SOB, recent travel, sick contacts, or rash. Of note, he has outpatient labs performed which demonstrated leukocytosis to 16 and abnormal LFTs.
Vitals: T 38.1C, HR 112, BP 98/58, RR 16, SpO2 99%
On physical exam, he had no abdominal tenderness and clear lung sounds bilaterally. The rest of his physical exam was generally unremarkable.
On arrival, he presented febrile, tachycardiac, and slightly hypotensive. Sepsis workup was initiated–patient was immediately given 1L fluids, tylenol, and ceftriaxone. Providing team had a high suspicion for PNA, however given abdominal symptoms of nausea and abnormal outpatient LFTs, they also performed a RUQ POCUS and obtained the following images:
From the RUQ US images above, we see a round lesion within the liver parenchyma with an anechoic center and hazy, irregular borders.
If you look closely at Image 2 and 3, there is a visible septation within the anechoic center however can be difficult to visual in some cases due to rib shadowing obscuring parts of the lesion.
These findings above raised suspicion for a possible hepatic abscess.
A CT abdomen and pelvis with IV contrast was obtained which revealed three hepatic lesions in this patient (measuring 8cm, 3cm, 3cm) fluid-filled structures with multiple thick septations concerning for hepatic abscesses.
Brief Overview of Hepatic Abscess (1,2,3,8)
Like abscesses elsewhere, hepatic abscesses are localized collections of necrotic inflammatory tissue within the liver
Usually occur due to infectious, malignancy-related, or iatrogenic causes. Infectious is most common.
Can be secondary to bacterial parasitic, or fungal agents
Affected populations with liver abscesses are generally linked to those in or traveling from a developing country. In these situations, parasitic liver abscesses are most common
However, bacterial abscess can also commonly be seen in the setting of comorbidities such as:
Immunocompromised
Diabetes mellitus (found in up to 15% of patient with hepatic abscesses)
Elderly
HIV/AIDS
Malignancy or chemotherapy/transplant recipients
ESRD
Biliary and/or pancreatic disease
IVDU
Abdominal sepsis or necrotizing enterocolitis
Trauma
Most bacterial abscesses are polymicrobial, with the most common bacterial agents being:
E. Coli
Klebsiella pneumoniae
The hypervirulent Asian strain has a particular predilection
Bacteroides
Anaerobic streptococci
Enterococci
Clinical presentation most commonly is fever and/or abdominal pain such as RUQ tenderness or guarding. About 50% of patients can also present with hepatomegaly and jaundice
Hepatic abscess are concerning from an EM standpoint as they can be associated with a number of serious complications such as:
Sepsis
Peritonitis from ruptured abscess
Portal vein or hepatic being thrombosis
Empyema
Ultrasound Findings and Utility of POCUS with Hepatic Abscesses (2,4,5,6,7)
Most commonly, hepatic abscess seen on POCUS within the ED have been incidentally caught with patients complaining of RUQ pain to evaluate hepatobiliary etiology
Ultrasound findings have been reported to be variable with hepatic abscesses, ranging from hypoechoic with well-rounded borders (Image 4) to heterogenous with irregular borders (Image 5)
Gas bubbles can also be seen (image 6)
Some may even have septations or debris present
Pyogenic abscesses are more likely to have a heterogenous pattern due to pus and debris it may contain
Abscess may rupture and present with perihepatic fluid
Image 4: Multilocular abscess in right liver lobe (hyperechoic with well-rounded borders)
Image 5: Large liver abscess (heterogeneous pattern with irregular borders)
Image 6: Two liver abscess with pneumobilia (gas is identified by hyperechoic, white speckled pattern within liver)
Due to the broad range and variable findings, US is limited in diagnosing a hepatic abscess. (sensitivity 85%)
Due to limitations of US, hepatic lesions as the one seen in the case and seen with other examples above can also be mistaken for other pathology such as possible hepatic mass. Hence, correlate clinically
CT with contrast is the diagnostic modality with a higher sensitivity of 97%
Despite this, some hepatic abscess can mimic malignancy even on CT. Hence patients ideally undergo IR drainage or biopsy for confirmation.
YET, hepatic abscess have a high mortality rate with significant potential complications. Hence, prompt recognition and resuscitation are key in successful treatment
Providers can take advantage of RUQ POCUS to quickly identify a potential hepatic abscess to narrow differentials, especially in the setting of sepsis and/or undifferentiated abdominal pain.
Management and Case Resolution (2)
Treatment is centered around administration of broad-spectrum antibiotics immediately, generally with gram-negative, gram-positive, and anaerobic coverage
Zosyn, metronidazole, and clindamycin are recommended
For abscesses >3cm, gold standard treatment is percutaneous drainage. Generally most successful for unilocular abscesses
However, if percutaneous drainage fails or if abscesses are >3-5cm and multiloculated surgical resection is a more effective treatment modality.
Coming back to our patient…
After the CT abdomen and pelvis with IV contrast was performed and identified three separate hepatic abscesses, general surgery was consulted.
Antibiotics were switched to zosyn. Patient was now afebrile and hemodynamically stable.
Per general surgery recommendations, patient was admitted to surgical step down unit for hemodynamic monitoring and percutaneous drainage of hepatic abscess via IR guidance.
The next day, about 30cc of purulent fluid was drained from the 8cm abscess.
Patient recovered well, was transitioned to the floor and eventually safe for discharge.
Patient was referred to return for outpatient IV antibiotic treatment until hepatic abscesses fully resolved.
Happy scanning!
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