case_images: PMC11834942_01
case_images: Abdominal MRI with intravenous contrast revealing a solid mass in the pancreatic tail (white arrow), which is round, well-defined, with regular margins, and measures 1.89 x 1.49 cm. The lesion appears slightly hyperintense compared to the surrounding normal pancreatic parenchyma on (A) axial T2-weighted image and (B) axial T2-weighted image with fat suppression. The lesion is isointense compared to the surrounding pancreatic parenchyma on (C) coronal T1-weighted image. No significant enhancement post-gadolinium contrast injection or infiltration into the adjacent structures is observed on (D) post-contrast coronal T1-weighted image.
case_images: cureus-0017-00000077662-i01.jpg
case_images: PMC11834942_01_cureus-0017-00000077662-i01.jpg
case_images: FIG1
case_images: T1-weighted imaging revealed no significant enhancement or evidence of infiltration into adjacent structures. These findings, combined with the patient's clinical presentation, strongly suggested an insulinoma (Figure 1).
case_images: (A) The operative view revealed a cystic mass located in the pancreatic tail (indicated by the green arrow). (B) The gross resected specimen showed the enucleated mass from the pancreatic tail with a solid and partially trabecular structure. (C) The post-operative view displayed the resected tumor.
case_images: cureus-0017-00000077662-i02.jpg
case_images: PMC11834942_01_cureus-0017-00000077662-i02.jpg
case_images: FIG2
case_images: Tumor enucleation revealed a mass measuring 3.5 x 2.5 x 1.5 cm located in the distal one-third of the pancreas (Figure 2).
case_images: (A-C) Histopathological images of the tumor cells at low, medium, and high magnifications, respectively, stained with hematoxylin-eosin. The tumor cells exhibit mild pleomorphism, minimal cytoplasm, and nuclei that are round, oval, and hyperchromatic. The stroma displays vascular dilation. (D) A high-magnification image showing the Ki-67 proliferation index, estimated at 5%. (E-G) Immunohistochemistry staining results (all at high magnification): (E) tumor cells showing positivity for synaptophysin, (F) tumor cells showing positivity for chromogranin, and (G) tumor cells showing positivity for insulin.
case_images: cureus-0017-00000077662-i03.jpg
case_images: PMC11834942_01_cureus-0017-00000077662-i03.jpg
case_images: FIG3
case_images: Based on the functional status and biological behavior, a definitive diagnosis of a well-differentiated (grade 2) P-NET was established (Figure 3).
case_images: Blood glucose levels from 7 days before surgery (D-7) to 4 days after surgery (D+4). The red line indicates the day of the surgery.
case_images: cureus-0017-00000077662-i04.jpg
case_images: PMC11834942_01_cureus-0017-00000077662-i04.jpg
case_images: FIG4
case_images: The levels of blood glucose before surgery and stabilization after surgery are depicted in Figure 4.