case_images: PMC10501723_01
case_images: Images obtained by conventional clinical examinations. (A, B) Magnetic resonance imaging of the abdomen. (A) T1-weighted image. (B) T2-weighted image. (C-F) Computed tomography (CT) scan of the nodule of the pancreatic tail. (C, D) Plain CT; (E, F) early phase of contrast-enhanced CT. (G)
  68Ga-labeled 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid-d-Phe1-Tyr3-octreotide (DOTATOC) positron emission tomography (PET)/CT. The white arrows indicate the nodule in the tail of the pancreas.
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case_images: The signal was isointense with the spleen on T1-weighted imaging, while on T2-weighted imaging, the signal was almost equivalent or slightly hypointense compared to the spleen ( Figures 1A, B ). 18F-fluorodeoxyglucose PET/CT showed no significant uptake in the nodule. Figures 1C-F ), which was adjacent to the spleen. Compared to the CT and MRI images at the age of 50, no apparent change of the tumor size was noted. DOTATOC PET/CT showed no significant uptake in the pancreatic tail nodule ( Figure 1G ).
case_images: [18F]FB(ePEG12)12-exendin-4 PET/CT for the pancreatic tail nodule. The arrows indicate the nodule in the tail of the pancreas. (A) Maximum intensity projection of PET 1 h after administration. The black arrow indicates the nodule in the tail of the pancreas, the blue arrows indicate the kidneys, and the green arrow indicates the bladder. (B) Fusion imaging of PET/CT 1 h after administration. The white arrow indicates the nodule in the tail of the pancreas. (C) Fusion imaging of PET/CT 2 h after administration. The white arrow indicates the nodule in the tail of the pancreas.
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case_images: The protocol was approved by the Kyoto University Certified Review Board (Y0074) and was conducted in accordance to the provisions of the Declaration of Helsinki. 18F-exendin-4 PET/CT demonstrated distinct uptakes in the pancreatic nodule at both 1 and 2 h after the intravenous probe administration ( Figures 2A-C ). The maximum standardized uptake values (SUVmax) of the nodule were 14.5 at 1 h ( Figure 2B ) and 12.7 at 2 h ( Figure 2C ), respectively. These uptakes were remarkably higher than the normal pancreas or surrounding organs except for the kidney and bladder ( Figure 2A ). No other focal uptakes were observed in the whole body ( Figure 2A ).
case_images: (A-G) Microscopic findings of the representative resected tumor. (A) Hematoxylin and eosin staining revealed a typical pancreatic neuroendocrine neoplasm, characterized by a trabecular proliferation of cells with oval nuclei and eosinophilic cytoplasm. (B-G) Immunohistochemical stains showed tumor cells positive for chromogranin A (B) and synaptophysin (C). The Ki-67 labeling index was 2.0% (D). The tumor cells were also positive for insulin (E), somatostatin receptor 2 (F), and glucagon-like peptide-1 receptor (G, H). Magnification: x400 (A), x200 (B-F,H), x40 (G), scale bar: 10 mum (A).
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case_images: In the histopathological examination of the tumor, hematoxylin and eosin staining revealed a typical well-differentiated pancreatic neuroendocrine neoplasm, characterized by a trabecular proliferation of cells with oval nuclei and eosinophilic cytoplasm ( Figure 3A ). In immunohistochemistry, the cells of the nodule were positive for chromogranin A ( Figure 3B ) and synaptophysin ( Figure 3C ). The Ki-67 labeling index was 2.0% ( Figure 3D ). The cells of the nodule were also positive for insulin ( Figure 3E ), SSTR type 2 ( Figure 3F ), and GLP-1R ( Figures 3G, H ).  Figure 3G  (low magnification image) indicates that GLP-1R is diffusely expressed in the tumorous component.  Figure 3H  (high magnification image) indicates that GLP-1R is expressed in almost all cells.