Pancreatic neuroendocrine microtumors in the elderly: A retrospective study using cadaveric pancreatic tissue

Figure 2 Histopathological changes of pancreatic neuroendocrine microtumors in Case 4. A: Hematoxylin and eosin staining of pancreatic neuroendocrine microtumors (PNEMTs) of Case 4; B: Immunostaining of PNEMTs in A with synaptophysin (Syn) antibody; C: Immunofluorescence staining of PNEMTs with glucagon (GLU) antibody; D: GLU (green) with insulin (red) double immunofluorescence staining. White asterisk in A: The tumors exhibited an organoid-like architecture, with tumor cells arranged in a trabecular pattern; black asterisk in A: The surrounding pancreatic parenchyma appeared largely normal. Black arrows in A: Indicate a slight membrane structure between the PNEMTs and the pancreatic tissue. Black arrowheads in A: Acinar ductal metaplasia; White arrows in C: GLU-positive cells in the islets of Langerhans; Black and white arrows in D: Insulin-positive cells in PNEMTs and islets of Langerhans, respectively. GLU: Glucagon; Syn: Synaptophysin; Ins: Insulin.