Hypoglycemic Syndrome in a Patient with Proinsulin-Only Secreting Pancreatic Adenoma (Proinsulinoma)
Figure 2
Histopathological analysis of the surgical specimen. (a) Hematoxylin and eosin staining (low magnification) showing gross appearance of the tissue and presence of a pseudocapsule with variable thickness. (b) Hematoxylin and eosin staining (200x) showing monomorphic cells with abundant granular cytoplasm and central nuclei, in contact with capillary basement membranes, stained with Period-Acid Schiff (PAS) reaction (c, 200x). (d) Capillaries are stained with anti-CD34 (200x). The strong chromogranin (e) and Synaptophysin (f) immunoreactivity indicates a neuroendocrine origin, while the few areas staining for cytokeratin-7 (g) are residual exocrine tissue (100x). A visual comparison between insulin (h) and proinsulin (i) staining (200x) suggests a stronger proinsulin immunoreactivity.
