Amyloid-Rich Pancreatic Neuroendocrine Tumors: a Potential Diagnostic Pitfall in Endoscopic Ultrasound-Guided Fine Needle Aspiration Cytology (EUS-FNAC).

摘要: Pancreatic neuroendocrine tumors (PanNETs) are rare neoplasms that include even rarer variants may pose different diagnostic problems, especially in fine needle aspiration cytology (FNAC). We describe the clues of amyloid-rich variant PanNETs endoscopic ultrasound (EUS)-guided (EUS-FNAC). Three cases with an stromal component were retrieved and retrospectively reviewed. For every case, pancreatic lesion was investigated by a EUS-FNAC procedure. The final diagnosis supported immunocytochemistry Congo red staining. All had similar features: neoplastic cells entrapped eosinophilic, homogeneous dense amorphous matrix. nature confirmed immunoexpression synaptophysin chromogranin A, while stroma characterized as amyloid based on positive Regarding hormonal profile, no insulin or proinsulin reactivity observed, but all diffusely for amylin. uncommon PanNETs, such amyloid-rich, is challenging procedures because unique misleading morphology, potentially mimicking fibrotic conditions deposition within systemic amyloidosis. In specimens, presence material requires to be considered differential phenotype.