Fasciola Hepatica Mimicking Malignancy on 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

Abstract

A 48-year-old female with complaints of gastrointestinal symptoms such as abdominal pain, fatigue, vomiting, nausea, and weight loss was diagnosed with neuroendocrine tumor after removal of a 2 mm lesion from the stomach with endoscopic biopsy. Her magnetic resonance imaging that was performed due to on-going symptoms showed multiple linear hypointense lesions in the liver. Positron emission tomography/computed tomography (PET/CT) scan was performed for differential diagnosis, which showed high fluorodeoxyglucose (FDG) uptake in these lesions. Clinical and laboratory findings revealed the final diagnosis as Fasciola hepatica. The imaging features of this case is presented to aid in differentiating this infectious disease from malignancy and avoid misdiagnosis on FDG-PET/CT.

Figure 1. A) Axial T2W magnetic resonance image showing extensive hyper-intense lesions along the portal triads on the left lobe of the liver (arrows), B) A contrast-enhanced T1W magnetic resonance image showing multiple, round, clustered hypo-intense lesions with peripheral contrast enhancement (arrows) in the liver, C) Axial T2W magnetic resonance image showing residual parenchymal hyper-intensity after treatment (arrows)

Figure 2. Positron emission tomography/computed tomography (PET/CT) findings of Fasciola hepatica. PET/CT scan was performed 60 min after i.v. injection of 256 MBq of ¹⁸F-fluorodeoxyglucose (FDG), using a lutetium oxyorthosilicate crystal equipped PET/CT (mCT20 Siemens, Germany). Maximum intensity projection images (A) show high FDG uptakes in different areas of the liver. Axial CT (C, E) images demonstrate hypodense lesions. FDG uptake (SUV_max: 5.8) in the 7^th (arrow heads) and (SUV_max: 5.2) 6^th liver segments (arrows) on axial PET/CT fusion images (B, D)