Primary hepatic neuroendocrine tumor — 18F-fluorodeoxyglucose positron emission tomography/computed tomography findings: A case report

Figure 1 Contrast-enhanced computed tomography images of the tumor. A: Non-contrast-enhanced computed tomography (CT) images reveal a 40 mm × 37 mm, well-circumscribed, heterogeneous hypoattenuating mass in the right lower lobe of the liver (arrow); B-D: Dynamic CT images demonstrate a rim-like enhancement of the tumor in the arterial phase (B); portal venous phase (C); and equilibrium phase (D). The tumor is less enhanced than the adjacent liver.

Figure 2 Positron emission tomography (PET) with 2-deoxy-2-[fluorine-18] fluoro-D-glucose images. On ¹⁸F-positron emission tomography/computed tomography imaging, the tumor shows increased uptake with a SUV_max of 5.1. Whole-body 2-deoxy-2-[fluorine-18] fluoro-D-glucose positron emission tomography reveals no abnormal extrahepatic activities.

Figure 3 Pathological findings. A: Hematoxylin and eosin-stained sections (× 200 magnification) demonstrate a well-differentiated neoplasm with the trabecular and glandular architectural pattern; B: The Ki-67 proliferation index (× 100 magnification) is 15% in tumor cells; C-F: Immunohistochemical staining (× 100 magnification) reveals positive immunoreactivities for CD56 (C), cytokeratin AE1/AE3 (D), synaptophysin (E), and negative immunoreactivity for chromogranin A (F), respectively.