Pancreatic endocrine tumour with ductules: further observations of an unusual histological subtype

Reconsideration of Clinicopathologic Prognostic Factors in Pancreatic Neuroendocrine Tumors for Better Determination of Adverse Prognosis

The question of how successful we are in predicting pancreatic neuroendocrine tumors (panNET) with poor prognosis has not been fully answered yet. The aim of this study was to investigate the effects of clinicopathological features on prognosis and to determine their validity in prediction of prognosis and whether a better prognostic classification can be made. Fifty-six patients who underwent pancreatic resection for pancreatic neuroendocrine tumor were included. The associations between clinicopathological parameters and prognosis were evaluated statistically. Efficiencies of different thresholds for tumor size, mitotic count, and Ki67 proliferation index for prognosis prediction were compared. Vascular invasion was statistically associated with high tumor grade, advanced pT stage, and mortality rate. The presence of non-functional tumor, lymphatic invasion, and > 10 cm tumor size were significantly related to shorter overall survival. Advanced pT stage (pT3-4), > 5 cm tumor size, and high tumor grade (grades 2-3) were significantly associated with shorter disease-free survival. The mortality rate showed the strongest statistical significance with mitotic count when grouped as 1: < 2, 2: 2-10, and 3: > 10 mitosis/ 2 mm². The 10% threshold value for Ki67 index was more successful in predicting adverse prognosis. Among the morphologic variants, the ductulo-insular variant was the most promising to have positive prognostic value in our series, although no statistical significance was detected. In conclusion, threshold values of 5 cm and 10 cm for tumor size, 10% for Ki67 proliferation index, and 10/2 mm² for mitotic count and vascular and lymphatic invasion assessed separately are potential prognostic candidates for better stratification of panNETs.

Intraductal polypoid lipid-rich neuroendocrine tumor of the pancreas with entrapped ductules: case report and review of the literature

Pancreatic neuroendocrine tumors of the main pancreatic duct are rare and usually small due to symptoms of pancreatic duct obstruction. We present a case of a large (3 cm), well-differentiated (G1) lipid-rich polypoid neuroendocrine tumor of the pancreas completely occluding the main pancreatic duct with non-neoplastic-entrapped ductules and CK19 positivity. Clinical, radiological, gross, microscopic, immunohistochemical, and ultrastructural findings are discussed. The literature pertaining to the unique features of this case is reviewed including clinical and pathologic pitfalls and the possible etiologic and prognostic significance of these findings.

Pancreatic endocrine tumors

The endocrine cells of the pancreas and their related cells throughout the gastrointestinal tract give rise to a variety of tumors that pose a diagnostic challenge. There has been progress in understanding their histogenesis, morphology, immunohistochemistry, molecular biology and classifications. This review will focus on nomenclature/terminology, classification, the role of immunohistochemistry, molecular advances, including genetic predisposition, and potential therapeutic targets to define the role of pathology in the application of prognostic and predictive markers for this disease.