METHODS: We report an unusual colonic MSI-MiNEN uncovered in an 89-year-old woman and the review of the literature.
RESULTS: Pathologic inspection revealed a high-grade carcinoma composed of tumor cells with neuroendocrine histologic traits and immunophenotype intermixed with mucin-containing signet ring-like cells arranged in nested and micronodular patterns. Loss of MLH1 and PMS2 mismatch repair proteins was detected in tumor cells. INSM1 immunostaining highlighted about 50% of the tumour, further reinforcing the MiNEN diagnosis. Next-generation sequencing identified multiple carcinogenic mutations. Because of the advanced stage of the tumor and its adhesion to the adjacent organs, surgical resection was aborted; immunotherapy was initiated. The tumor is in remission 30 months following initiation of treatment, and the patient remains asymptomatic.
CONCLUSIONS: This unique MSI MiNEN was characterized by its immunohistochemical and molecular signatures and illustrated how correctly diagnosing MSI can strongly improve a patient\'s outcomes.
方法:我们报告了一个在89岁女性中发现的不寻常的结肠MSI-MINEN,并对文献进行了综述。
结果:病理检查发现,由具有神经内分泌组织学特征和免疫表型的肿瘤细胞与巢状和微结节状排列的含粘蛋白的印戒样细胞混合组成的高级别癌。
结论:这种独特的MSIMiNEN以其免疫组织化学和分子特征为特征,并说明了如何正确诊断MSI可以大大改善患者的预后。