Neuroendocrine carcinomas (NECs) are rare and high-grade neuroendocrine neoplasms (NENs) that arise from various organs, and the prognosis in advanced cases is reported to be 8 to 13 months.1,2,3 The 2010 World Health Organization (WHO) classification system4 introduced a grading scheme based on mitotic counts or Ki-67 index, classifying NENs into 3 tiers (grades 1-3). This evidence concerns the gene MKI67 and neuroendocrine neoplasm.