摘要目的:探讨SWI/SNF缺失型鼻腔鼻窦癌的临床病理学特征、免疫表型及预后。方法:收集2019年1月至2024年12月首都医科大学宣武医院确诊的13例SWI/SNF缺失型鼻腔鼻窦癌，分别进行临床资料分析、HE染色观察及免疫组织化学染色。结果:患者男性10例，女性3例，年龄33~81岁，中位年龄59.0（41.5，64.5）岁。影像学表现为鼻腔鼻窦占位性病变。镜下肿瘤以中等-大巢片状浸润性生长为主，细胞形态较单一，主要呈基底样，和/或小细胞样，1例复发病例肿瘤细胞呈上皮样；7/13例伴有局灶坏死。免疫组织化学染色结果显示，7例SMARCA4/BRG1表达缺失，6例SMARCB1/INI1表达缺失，5例同时伴有SMARCA2表达缺失，13例CKpan均不同程度阳性，10例EMA阳性，5例p63/p40部分阳性；神经内分泌标志物中，10例灶状表达突触素或CgA，Ki-67阳性指数40%~90%；PD-L1染色结果为3例SMARCB1缺失型鼻腔鼻窦癌综合阳性评分（CPS）≥1，其他10例CPS<1。13例患者中，失访2例，死亡6例，患者于术后1~25个月死亡，存活5例，最长存活时间130个月，随访时间8~130个月。结论:SWI/SNF缺失型鼻腔鼻窦癌是头颈一类少见的未分化癌，具有特殊的病理形态学和分子遗传学改变；SMARCA4缺失型及SMARCB1缺失型鼻腔鼻窦癌的肿瘤细胞形态均可表现为基底样或小细胞样；与SMARCB1缺失型相比，SMARCA4缺失型鼻腔鼻窦癌的鳞状上皮标志物表达明显下降，而倾向于更多地表达神经内分泌标志物；PD-L1染色阳性的结果更倾向发生于SMARCB1缺失型病例。SWI/SNF缺失型鼻腔鼻窦癌同时伴有SMARCA2共缺失的病例预后更差。综合病理形态、免疫组织化学及分子遗传学特征对于诊断该类罕见肿瘤具有重要意义。

abstractsObjective:To investigate the clinicopathological features, immunophenotype and prognosis of SWI/SNF complex-deficient sinonasal carcinomas.Methods:The clinicopathological, immunohistochemical profiles of 13 SWI/SNF complex-deficient sinonasal carcinomas diagnosed at Xuanwu Hospital, Beijing, China between Januay 2019 and December 2024 were reviewed and followed up.Results:The patients′ ages ranged from 33-81 years, median 59.0 (41.5, 64.5) years, including 10 males and 3 females. Imaging findings showed space-occupying lesions in the nasal cavity and sinuses. Microscopically, tumors predominantly exhibited invasive growth in medium-to-large nests or sheets, with relatively uniform morphology, mainly basaloid and/or small cells, while one recurrent case displayed epithelioid morphology. Focal necrosis was observed in 7 cases. Immunohistochemical results showed loss of SMARCA4/BRG1 in 7 cases, loss of SMARCB1/INI1 in 6 cases, and concurrent loss of SMARCA2 in 5 cases. CKpan was expressed to varying extent in all cases, 10 cases were EMA positive, and 5 cases were partially positive for p63/p40. Among neuroendocrine markers, 10 cases showed focal expression of syn or CgA. The Ki-67 proliferation index ranged from 40% to 90%. PD-L1 staining showed combined positive score (CPS) was ≥1 in 3 SMARCB1-deficient cases (CPS ranging from 2 to 3) and CPS <1 in the other 10 cases. Among the 13 patients, 2 were lost to follow-up, 6 died (postoperative survival: 1-25 months), and 5 remained alive, with the longest survival time of 130 months (follow-up range, 8-130 months).Conclusions:SWI/SNF complex-deficient sinonasal carcinoma is a rare undifferentiated malignancy in the head and neck, characterized by distinct pathological and molecular genetic features. SMARCA4-deficient and SMARCB1-deficient carcinomas both exhibit basaloid or small cell-like morphology. Compared to SMARCB1-deficient carcinomas, SMARCA4-deficient carcinomas show reduced expression of squamous cell markers but increased expression of neuroendocrine markers. The positive PD-L1 staining is more likely present in SMARCB1-deficient carcinomas than SMARCB4-dificient ones. Co-loss of SWI/SNF and SMARCA2 correlates with poorer prognosis. Comprehensive evaluation of histopathology, immunohistochemistry, and molecular genetics is critical for accurately diagnosing this rare entity.