Successful treatment of a pancreatic schwannoma by spleen-preserving distal pancreatectomy

Figure 1 Ultrasound findings. A: Ultrasound showed a well-defined, low-density lesion (arrow) measuring 3.7 cm × 2.3 cm in the pancreatic neck and body; B: No blood flow signal within the lesion was detected by color Doppler ultrasound.

Figure 2 Computed tomography findings. A: An unenhanced CT scan revealed a well-marginated and hypodense mass (arrow) measuring 2.8 cm × 1.9 cm in the pancreatic neck and body; B: On contrast-enhanced CT, the mass was slightly and heterogeneously enhanced.

Figure 3 Microscopic examination. A: A thin capsule (black arrow) was found between the tumor (red arrow) and the normal pancreatic tissues (green arrow) (HE, × 40); B: The tumor cells were spindle-shaped and had a palisading arrangement with no atypia, which is compatible with a benign tumor. Both hypercellular and hypocellular areas were visible (HE staining, × 200). HE: Hematoxylin and eosin.

Figure 4 Immunohistochemical staining. The tumor cells were strongly positive for S-100 protein (HE staining, × 200). HE: Hematoxylin and eosin.