Large Cell Neuroendocrine Carcinoma (LCNEC) Associated with a Dysplastic Sessile Serrated Lesion (SSL) and Deficient Mismatch Repair (MMR) Protein: A Case Report.

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Introduction: Colorectal poorly differentiated neuroendocrine carcinomas (NECs) are rare, but extremely aggressive. The mechanisms of their carcinogenesis and aggressiveness are still largely unknown. Recently Nobuyoshi Takizawa showed that the molecular features of colorectal NECs are similar to those of adenocarcinoma and not to those of NETs and they were more evident in small cell NECs than in large cell NECs. This is supported by combined cases with conventional adenoma/adenocarcinoma and NECs. Stelow et al showed that DNA mismatch repair proteins were intact in 14/15 colorectal small cell NECs. Two cases of LCNECs arising from SSL have been reported so far in the literature.

Aim(s): NA

Materials and methods: NA

Conference: 15th Annual ENETSConcerence (2018)

Presenting Author: Luong T

Authors: Luong T, Nisa Z,

Keywords: Large cell neuroendocrine carcinoma, sessile serrated lesion, microsatellite instability, MMR protein, BRAF mutation,