摘要目的:探讨食管基底层型高级别异型增生的临床病理学特征。方法:收集2009—2019年间解放军联勤保障部队第九八九医院平顶山医疗区（原第一五二中心医院）34例和首都医科大学附属北京朝阳医院18例食管基底层型高级别异型增生的病例，共计52例，收集患者的临床病理资料，观察组织形态学特征和免疫表型，并结合文献进行探讨。结果:患者中位年龄64岁（范围43~72岁），男性35例，女性17例，男女比为2.1∶1.0。食管上段8例，中段41例，下段3例。按巴黎分型0-Ⅱb型24例，0-Ⅱc型28例。内镜下病变色泽发红，边缘不整齐。窄带成像病变呈褐色或茶褐色，放大观察黏膜表面微血管异常，有边界形成。碘染色病变不着色或淡染，边界不规则。组织学上，鳞状上皮基底侧上皮细胞密度增加，细胞核大、深染，排列紊乱或极性丧失，肿瘤向下生长形成浸润性鳞状细胞癌的比例高。免疫组织化学染色，肿瘤p53突变率为48.6%（18/37）。Ki-67阳性指数中位数为60%（范围20%~90%）；基底层细胞Ki-67阳性细胞数中位数为26个/HPF（范围5~70个/HPF）。Ki-67异常分布模式37例（100.0%）。原病理诊断为低级别异型增生8例，不典型性上皮细胞2例，高级别异型增生42例。结论:食管基底层型高级别异型增生形态特殊，肿瘤主要局限于鳞状上皮层的下半部分，具有重度细胞学异型性，侵袭性强，疾病早期易发展成浸润性鳞状细胞癌。病理上误诊为低级别病变的比例高。p53突变和Ki-67异常分布模式有助于此类高级别异型增生的诊断。

abstractsObjective:To investigate the clinicopathological features of basal cell layer type high-grade squamous dysplasia of the esophagus.Methods:Fifty-two cases of basal cell layer type high-grade squamous dysplasia of the esophagus were collected at PLA Joint Logistics Support Force 989 Hospital (34 cases) and Beijing Chaoyang Hospital (18 cases) from 2009 to 2019. The clinical, histological and immunohistochemical features were characterized. Related literature was also reviewed.Results:The median age of the 52 patients was 64 years (range 43-72 years). There were 35 men and 17 women, with a male to female ratio of 2.1∶1.0. There were 8 cases in the upper esophagus, 41 in the middle esophagus and 3 in the lower esophagus. According to the Paris Classification, 24 cases were 0-Ⅱb and 28 cases were 0-Ⅱc. Endoscopic examination showed that the color of the lesions was red and the edge was irregular. The narrow band imaging showed that the lesions were brown, and the microvascular abnormalities on the mucosal surface were observed with high magnification. Iodine staining of the lesions showed no or light staining and irregular border. Histologically, the basal layer of squamous epithelium was hypercellular, with large and hyperchromatic nuclei, and disordered cell arrangement. A high proportion of the cases showed a down-growth pattern and associated invasive squamous cell carcinoma. The immunohistochemical staining of 37 cases showed that the mutation rate of p53 was 48.6% (18/37), the median of Ki-67 labeling index was 60% (range 20%-90%), the median of Ki-67 labeling index of the basal tumor cells was 26/HPF (range 5-70/HPF), and the rate of abnormal Ki-67 distribution pattern was 37(100.0%). According to the initial pathological diagnosis, there were 8 cases of low-grade intraepithelial neoplasia, 2 cases of atypical epithelial cells and 42 cases of high-grade intraepithelial neoplasia.Conclusions:The basal cell layer type high-grade squamous dysplasia of the esophagus has a unique morphology. The dysplasia is mainly limited to the lower half part of the squamous epithelium. With marked cytological atypia and prominent invasiveness pattern, it is likely to develop into invasive squamous cell carcinoma at an early stage of the disease. The rate of pathologic misdiagnosis (such as low-grade lesion) is high. The p53 mutation and Ki-67 abnormal distribution pattern are helpful features for confirming the diagnosis of such high-grade dysplasia.