Miguel Quirch MDa, Hawa Edriss MDb
Correspondence to Miguel Quirch MD
Email: Miguel.quirch@ttuhsc.edu
SWRCCC 2016;4(16)61-62
doi: 10.12746/swrccc2016.0416.222
A
29-year-old Hispanic man from prison with no significant past medical history
presented with excessive thirst, vomiting, and diarrhea for one week and
subjective fever and chills for one month. The patient denied abdominal pain. On
arrival, his temperature was 99 F, heart rate 108 beats/minute, respiratory rate
36 breaths/minute, and SpO2 94%. His physical examination was
significant for dry mucous membrane and icteric sclera. Laboratory studies
revealed a white blood count of 34.9k/μL, INR 1.6, amylase 169 unit/L, lipase
1060 unit/L, BUN 94 mg/dl, creatinine 6.4 mg/dL, sodium 120 mmol/L, bicarbonate
16mmol/L, alkaline phosphate 275 unit/L, total bilirubin 8.2 mg/dl, direct
bilirubin of 6.9 mg/dl, and AST/ALT of 73/57 unit/L. Computed tomography of the
abdomen revealed a hepatic mass
greater than 10 cm in diameter with
multiple thick septae in both the right and left
hepatic lobes suspicious for abscess or tumor (Figure). Amoeba and echinococcus
ELISA tests and an E. histolytica
antigen assay were negative. The patient underwent CT guided drainage by
interventional radiology (IR). Blood and hepatic
drainage cultures grew
Streptococcus intermedius; the aspirate had a
negative AFB stain. The patient was initially treated with broad-spectrum
antibiotics (IV meropenem and vancomycin) and then switched to IV ceftriaxone
based on sensitivity results. He subsequently underwent two more IR drainage
procedures with a catheter left in place. Since patient continued to have bloody
drainage, the surgery team was consulted, and they recommended a liver biopsy to
exclude malignancy. A surgical biopsy showed reactive liver tissue with
cholestasis and no malignancy.
A pyogenic liver abscess usually presents with nonspecific symptoms and
can take from two weeks to more than one month to develop and present with
symptoms. These symptoms typically include malaise, fever/chills,
nausea/vomiting, weight loss; only half of patients have right upper quadrant
symptoms. Poor prognostic indicators include a bilirubin >3.5mg/dl and the
presence of multiple abscesses. Mortality ranges between 3-30% even with early
identification and optimal therapy. The three most common etiological causes of
liver abscess are polymicrobial (pyogenic) infection which accounts for 80% of
cases, amebic infection (10%), and fungal infection (<10%), most frequently due
to Candida species. After right
upper abdominal quadrant pathology is suspected, an abdominal ultrasound is
usually the first imaging study ordered. Ultrasonography uses high frequency
sounds that are deflected, refracted, and reflected off tissue to create an
image, with the boundaries between tissue forming visible differences on the
images. Ultrasound can help to distinguish biliary disease from hepatic disease;
it identifies pathology >1cm in diameter.1 It is particularly
useful in identifying amebic abscesses which typically appear as oval or round
masses near the liver capsule, are hypoechoic with low-level internal echoes,
and do not have significant wall echoes compared to pyogenic abscesses, which
can appear as either discrete hypoechoic nodules or as ill-defined areas of
distortion. 2 Abdominal CT scan is the next step and provides
information on the extent of disease and precise localization for guided
drainage. Computed tomography uses an emitter sending x-ray beams through tissue
to a detector, forming cross sections of tissue. A hepatic abscess appears as a
well-demarcated mass, hypodense to surrounding liver parenchyma. A double target
sign on dynamic studies and an enhanced rim sign can be seen when contrast used.
Gas is detected in 20% of these lesions. It is more sensitive than ultrasound in
detecting pyogenic abscess (95-100% vs 80-90%), solid masses, and small
microabscesses, but it is not as accurate distinguishing amebic abscesses when
compared to ultrasound. Radiography of the chest helps exclude pleural or
pulmonary pathologies and can identify extension or rupture of an abscess.
Therapeutic percutaneous needle aspiration (PNA) or percutaneous catheter
drainage (PCD) and antibiotics are needed for definitive treatment. Surgical
exploration is reserved for large abscesses >5cm in size, complicated abscesses,
and abscesses resistant to treatment.1 Older studies suggested that
serial PNAs were the best treatment option, but more recent studies have shown
that PCD has higher success rates, reduces the time required to achieve clinical
relief, and results in a 50% reduction in abscess cavity size.3
Provided that the abscess resolves both drainage methods result in comparable
long term outcomes.4
References
1. Vogt D, Ferri F, Anand B. Liver Abscess. ClinicalKey, Elsevier, BV,
February 2, 2012. (Accessed August 25, 2016, at
https://www-clinicalkey-com/#!/content/medical_topic/21-s2.0-1010020).
2. Mortele K, Segatto E, Ros P. The infected liver: radiologic-pathologic
correlation. RadioGraphics 2004; 24(4):937-955.
4. Cai Y, Xiong X, Lu J et al. Percutaneous
needle aspiration versus catheter drainage in the management of liver abscess: a
systematic review and meta-analysis. International Hepato-Pancreato-Biliary
Association 2015; 17(3):195-201.
Received: 8/7/2016
Accepted: 9/19/2016
Author Affiliation: Miguel Quirch is a resident in Internal
Medicine at Texas Tech University Health Sciences Center
in Lubbock, TX. Hawa
Edriss is a fellow in Pulmonary and
Critical Care Medicine at TTUHSC in
Lubbock, TX.
Reviewer: Eman Attaya MD
Published
electronically: 10/15/2016