Large liver abscess caused by ingestion of fishbone

An 83-year-old female presented with epigastric pain, nausea, vomiting and a fever of 38.9º C. Physical examination revealed epigastric and left upper quadrant pain on palpation. The laboratorial study showed leucocytosis and a significant increase in C-reactive protein levels.

Ultrasound (figure 1) revealed a large liver lesion with a very heterogeneous echogenicity and some areas of ring-down artifact, that were suggestive of gas foci. Subsequently, a CT scan was performed (figure 2) revealing a prominent liver lesion with liquid areas, gas foci, and enhancing septa. These findings were suggestive of a liver abscess. In addition, the dense linear structure inside the lesion corresponded to a fish bone. The fishbone probably perforated the gastric wall, migrating to the liver, and causing the abscess.

Background

Foreign body ingestion is common. Despite that, it can cause various complications that can resolve spontaneously or result in life-threatening events. The most common foreign bodies to cause perforation are fishbones. As most fishbones are radiolucent, CT is usually the best detection method [1].

Clinical Perspective

The patient rarely reports the ingestion of the foreign body, so the degree of clinical suspicion is generally low. In addition, the manifestation is frequently nonspecific. Therefore, analysing CT findings with high suspicion is essential for establishing the diagnosis [2].

Liver abscess is the most common type of visceral abscess. Liver abscesses can result from multiple causes, such as ascending cholangitis; hematogenous dissemination via the portal vein or disseminated sepsis via the hepatic artery; or direct inoculation from either penetrating trauma or an iatrogenic procedure. Clinical presentations contain a wide range of symptoms, but the classical ones are fever and abdominal pain, usually in the right upper quadrant [3-5].

Imaging Perspective

The classic CT appearance of a hepatic abscess is a well-defined, low-attenuation, round mass with an enhancing peripheral rim. Abscesses can display as a simple fluid collection, a single multiloculated cystic mass, a solid (phlegmonous) process, or multifocal lesions. The “double target sign” is a characteristic imaging feature of hepatic abscess seen on contrast-enhanced CT images when a high-attenuation inner ring and a low-attenuation outer ring surround a central low-attenuation fluid-filled area. An air-fluid level or tiny bubbles of gas may be present and, despite not being specific, are characteristic of abscesses [3]. When a foreign digestive body is the cause of a hepatic abscess, it is not always possible to provide evidence of the site of visceral perforation by imaging. Despite that, the presence of a foreign body in the lesion is highly suggestive of that cause [4,5].

On ultrasound, liver abscesses are usually heterogeneous masses with variable echogenicity, therefore they may simulate solid lesions and require a sectional method to diagnose. Gas foci may show dirty shadowing or ring-down artefact [3].

Outcome

In the case of liver abscess, antimicrobial therapy is mandatory. Image-guided drainage is also useful and proven to reduce mortality. Surgical treatment may be required in some cases [3].In this case, a multidisciplinary team decided to do antimicrobial therapy and to drain the abscess. The patient’s inflammatory parameters improved during hospitalisation, and she was discharged in good clinical condition.

Take Home Message / Teaching Points

• Accidental ingestion of fishbones is a known cause of visceral perforation.
• Liver abscesses can be caused by visceral perforation.
• An abscess should be considered in a gas-containing liver lesion.
• The classic CT appearance of a hepatic abscess is a well-defined, low-attenuation, round mass with an enhancing peripheral rim.