Misdiagnosis of food-borne foreign bodies outside of the digestive tract on magnetic resonance imaging: Two case reports

Abstract

Background: Patients with foreign bodies in the digestive tract are often encountered, but complete penetration of a foreign body through the gastrointestinal tract is rare, and the choice of imaging method is very important. Improper selection may lead to missed diagnosis or misdiagnosis.

Case summary: An 81-year-old man was diagnosed as having a liver malignancy after he took magnetic resonance imaging and positron emission tomography/computed tomography (CT) examinations. The pain improved after the patient accepted gamma knife treatment. However, he was admitted to our hospital 2 mo later due to fever and abdominal pain. This time, he received a contrast-enhanced CT scan, which showed fish-boon-like foreign bodies in the liver with peripheral abscess formation, then he went to the superior hospital for surgery. It lasted for more than 2 mo from the onset of the disease to the surgical treatment. A 43-year-old woman with a 1 mo history of a perianal mass with no obvious pain or discomfort was diagnosed as having an anal fistula with the formation of a local small abscess cavity. Clinical perianal abscess surgery was performed, and fish bone foreign body was found in perianal soft tissue during the operation.

Conclusion: For patients with pain symptoms, the possibility of foreign body perforation should be considered. Magnetic resonance imaging is not comprehensive and that a plain computed tomography scan of the pain area is necessary.

Keywords: Acute abdomen; Bowel perforation; Buttocks foreign body; Case report; Fish bone; Liver foreign body.

Figure 1

An 81-year-old man was admitted to our hospital with abdominal pain. A: Magnetic resonance imaging showed mixed-signal shadows in the liver, and an enhanced scan showed uneven enhancement (arrow); B: Two months later, computed tomography images showed a strip-like shadow of bone density in the liver, and the edge of the shadow was sharp (arrow).

Figure 2

A 43-year-old woman was admitted to our hospital with hip pain. A: Magnetic resonance imaging showed abnormal tubular signals behind the anal canal, obvious local enhancement on an enhanced scan, but no enhancement in some layers. Additionally, exudation was observed in the surrounding subcutaneous fat (arrow); B: A low signal bar with very clear and smooth edges was present, but sharp edges were evident on oblique coronal images (arrow).