Percutaneous and intraoperative aspiration biopsy cytology of pancreatic neuroendocrine tumors : Cytomorphologic study with an immunocytochemical contribution

To evaluate the efficacy and accuracy of fine needle aspiration biopsy (FNAB) in the diagnosis and recognition of pancreatic neuroendocrine tumors (NETs). The study group consisted of six cases of pancreatic tumors correctly diagnosed or strongly suggested to be NET based on fine needle aspiration biopsy (FNAB) cytology and was retrospectively reviewed. Also reviewed and examined were the immunocytochemical (ICC) stains applied to five of the aspirates and electron microscopic (EM) study done on one case. Five cases were collected by computed tomography (CT)-guided aspiration, and one case was obtained intraoperatively by the surgeon. All six cases showed characteristic cytomorphologic features sufficient for their recognition and separation from pancreatic adenocarcinoma and other lesions. The ICC staining results and EM study were very helpful in confirming the cases' neuroendocrine cell origin. Histologic confirmation was available for four cases. Intraoperative and CT-guided FNAB of the pancreas is a valuable method in the recognition of NET of the pancreas, particularly when coupled with ICC studies and appropriate clinical and radiologic settings.