Abstract Library

#2714 The Clinical Outcome of Non-Curative Resection of Small Rectal Neuroendocrine Tumours

Introduction: Small rectal NETs are thought to be less aggressive and relatively benign. However, lymphovascular invasion(LVI) or positive margin after endoscopic resection(ER) was noticed in small rectal NETs.

Conference: 17th Annual ENETSConcerence (2020)

Presenting Author:

Authors: Hu H, Li R, Xu R, Zhang S,

Keywords: rectal neuroendocrine tumors, lymphovascular invasion, non-curative, endoscopic resection,

#1715 Recurrence of 6mm Rectal Neuroendocrine Tumor, 14 Years after Excision

Introduction: Rectal neuroendocrine tumours (NET) constitute 25% of all the digestive NET. Predictive factors of distant metastasis are: size greater than 1cm, high proliferative index and muscularis or lymphovascular invasion. In the absence of these criteria, some authors advocate there is no need for long-term follow-up.

Conference: 14th Annual ENETSConcerence (2017)

Presenting Author: Marques B

Authors: Marques B, Martins R, Cadime A, Marques M, Couto J,

Keywords: neuroendocrine, recurrence,

#106 Gastroenteropancreatic neuroendocrine tumors: single institution clinicopathological study

Introduction: Neuroendocrine cells are widely distributed throughout the body, and neoplasms from these dispersed cells can arise at many sites. They are distinguished into two broad categories: 1) Tumors identified as small cell lung carcinomas with biology and natural history of a high-grade malignancy and characteristics of small cell undifferentiated or anaplastic appearance by light microscopy. The WHO categorizes these tumors as poorly-differentiated neuroendocrine carcinomas; 2) Well-defined neuroendocrine tumors (NETs) with variable, but most lyindolent biologic behavior and characteristic well-differentiated histologic features. The majority arise in the gastrointestinal tract and collectively they are referred as gastroenteropancreatic neuroendocrine tumors (GEP/NETs). They include carcinoid tumors, pancreatic islet cell tumors (gastrinoma, insulinoma, glucagonoma, VIPoma, somatostatinoma), paragangliomas, pheochromocytomas, and medullary thyroid carcinomas. The WHO classifies the GEP/NETs as well-differentiated NETs (carcinoid tumors) if they are noninvasive and have benign behavior or uncertain malignant potential. In contrast, GEP/NETs with characteristics of low-grade malignancy with invasion of the muscularis propria or beyond, or metastases, are characterized as well-differentiated neuroendocrine carcinomas (malignant carcinoids). Pancreatic islet cell tumors, whether functioning or not, are classified as well-differentiated NETs or well-differentiated neuroendocrine carcinomas, due to the (depending on) histologic characteristics. The WHO classification for gastroenteropancreatic NETs based on stage (ie size and presence of metastases) and grade (mitotic rate, perineural and lymphovascular invasion, Ki-67 proliferative index) categorizes them as well-differentiated NETs, e.g., carcinoid tumors, or as well-differentiated neuroendocrine carcinomas.

Conference: 7th Annual ENETSConcerence (2010)

Presenting Author: Papaxoinis G

Authors: Vaslamatzis M, Papaxoinis G, Tsiga A, Mantzaris G, Exarchos D,

Keywords: gastroenteropancreatic, neuroendocrine, tumors, pathology, characteristics, treatment,

#87 Alterations of E-cadherin, beta-catenin and caveolin-1 expression in gastroenteropancreatic neuroendocrine tumors

Introduction: Gastroenteropancreatic neuroendocrine tumors (GEP NETs) comprise a heterogeneous group of neoplasm with different histological patterns and biological behavior. Only limited information is available on immunohistochemical prognostic factors of disease. Alterations in the cell-cell adhesion system are closely associated with cell invasion and metastasis in many malignancies, including those of endocrine origin. Abnormal expression of E-cadherin and beta-catenin has been reported to play an important role in these processes. Caveolin-1 has recently been identified as a tumor metastasis modifier factor, which might increase the cell metastasis potential through the interaction with E-cadherin. However, the role of caveolin-1 in GEP NETs cell invasion remains unknown.

Conference: 7th Annual ENETSConcerence (2010)

Presenting Author:

Authors: Delektorskaya V, Chemeris G,

Keywords: immunohistochemistry, E-cadherin, beta-catenin, caveolin-1, cyclin D1, Ki67, gastroenteropancreatic neuroendocrine tumors, metastasis,