INSM1 and neuroendocrine neoplasm: INSM1 was positive in 82.9% of well-differentiated neuroendocrine tumors (58/70), 85.0% of poorly differentiated neuroendocrine carcinomas (17/20), 72.7% of low-grade goblet cell adenocarcinomas (8/11) (grade 1), and 66.7% of high-grade goblet cell adenocarcinomas (6/9) (grade 2/3).