探讨鼻腔鼻窦高级别非肠型腺癌（non-ITAC）的病理学诊断与鉴别诊断特征、组织起源、治疗及预后。

对2例罕见的鼻腔鼻窦高级别non-ITAC进行组织形态分析、免疫组织化学及原位杂交研究，并复习相关文献。

男女患者各1例，年龄分别为50岁和60岁，均因鼻腔反复出血数月入院，CT检查提示分别为右侧和左侧鼻腔鼻窦占位。镜下见肿瘤细胞异型性明显，细胞凋亡与病理性核分裂象易见，这些瘤细胞主要排列成梁状、缎带状等结构伴点灶状坏死，局部形成原始腺腔样结构，并可见与表面上皮有移行。免疫组织化学检测显示肿瘤细胞广泛表达广谱细胞角蛋白，并不同程度地表达细胞角蛋白（CK）7、CK18，并表达INI-1，而尾型同源盒转录因子2、CK20、黏蛋白2、绒毛蛋白、嗜铬素A、突触素、神经元特异性烯醇化酶、P63、CK5/6、雄激素受体、巨囊性病液体蛋白15、HMB45、MelanA、S-100、甲状腺转录因子-1、天冬氨酸蛋白酶A和波形蛋白均不表达，Ki-67增殖指数70%~90%；原位杂交检测EBER阴性。

鼻腔鼻窦高级别non-ITAC是一种极为罕见的恶性肿瘤，除手术及放射治疗和化学治疗外，缺乏有效的治疗手段，预后差，需要准确诊断。同时，由于该肿瘤具有很强的组织形态异质性，且缺乏相关的分子生物学研究，需借助免疫组织化学检测与多种肿瘤鉴别，其诊断常是一种排他性诊断。

To explore the clinicopathological characteristics of sinonasal high-grade non-intestinal type adenocarcinoma (non-ITAC) and to investigate its diagnosis, differential diagnosis, histological origin, therapy, and prognosis.

Histomorphological, immunohistochemical, and in situ hybridization studies were performed on two rare cases of sinonasal high-grade non-ITAC, and the relevant literature was reviewed.

One male and one female patient, aged 50 and 60 years, respectively, were admitted to the hospital for several months due to repeated nasal bleeding. CT indicated that the right and left nasal cavity were occupied, respectively. Microscopically, the tumor cells showed obvious atypia, apoptosis, and pathological mitosis. These cells were mainly arranged in a trabecula and ribbon structure with necrosis, forming primitive glandular cavity in the focal area and migrating to the surface epithelium. Immunohistochemistry showed that pan-cytokeratins were widely expressed in tumor cells, and CK7 and CK18 were positively expressed to varying degrees, while CDX2, CK20, Mucin2, Villin, chromogranin A, synaptophysin, NSE, P63, CK5/6, androgen receptor, gross cystic disease fluid protein-15, HMB45, MelanA, S-100, thyroid transcription factor-1, NapsinA, and Vimentin had negative expression. Ki-67 proliferation index was 70%-90%. In situ hybridization showed EBER negativity.

Sinonasal high-grade non-ITAC is an extremely rare malignant tumor. In addition to surgery and chemoradiotherapy, it lacks effective treatment and has a poor prognosis, so an accurate diagnosis is required. Due to its high histomorphological heterogeneity and the lack of relevant molecular biology research, a differential and exclusive diagnosis is often required to be performed by immunohistochemistry.