伴有小管形成的膀胱巢状变异型尿路上皮癌临床病理观察

Clinicopathological features of nested variant of urothelial carcinoma with tubule formation

目的探讨伴有小管形成的膀胱巢状变异型尿路上皮癌的临床病理特征、诊断与鉴别诊断及预后,提高对该病的认识。方法应用常规HE和免疫组化染色及光镜观察1例伴有小管形成的膀胱巢状变异型尿路上皮癌,通过组织病理学特征及结合相关文献进行分析。结果患者男性,48岁。首发症状为全程肉眼血尿。镜下可见圆形或多边形的小管状结构弥漫分布,排列不规则,偶可见巢状结构;肿瘤细胞形态温和,中等大小,圆形居多,胞质丰富;胞核异型性小,核浆比轻度升高,稍大于正常细胞,核深染少见,未见病理性核分裂象,染色质纤细,核仁不显著;肿瘤细胞浸润至肌层,细胞异型性增加,呈多边形,核增大,核染色质变粗;肿瘤周围可见间质纤维化;无血管、淋巴管及神经侵犯。免疫组化示MOC31、BreEp4灶状(+),CK7、CK5/6、p63、CK34betaE12及p53均(+),CK20、Villin、CDX-2、TTF-1、PSA、P504S、PAX-8均(-),Ki-67增殖指数为10%。结论伴有小管形成的膀胱巢状变异型尿路上皮癌是膀胱尿路上皮癌的一种罕见变异型,与膀胱的非肿瘤性病变难以鉴别。确诊主要依赖于生物学上呈现出的不规则浸润模式,免疫组化可作为诊断这类病变的辅助手段。

Objective To investigate the clinicopathological features,diagnosis,differential diagnosis and prognosis of nested variant of urothelial carcinoma with tubule formation.Methods Conventional H&E staining and immunohistochemistry of EnVision method were used to observe a case of nested variant of urothelial carcinoma with tubule formation under light microscope.The histopathological features were analyzed and related literatures were reviewed.Results A male patient aged 48 years.The first symptom was gross hematuria.Under microscope,the circular or polygonal small tubular structure was diffusely distributed and irregularly arranged,and structure of small nests was seen occasionally;the tumor cells were mild in morphology,medium in size,round in shape,and rich in cytoplasm.The nuclear atypia was bland,the nuclear/cytoplasm ratio was slightly elevated,nuclear deep staining was rare,and pathological mitotic figure was not seen.The tumor cells had granular chromatin with inconspicuous nucleoli.Tumor cells infiltrated into the muscular layer,which made cell dysplasia increased,nuclear enlarged and nuclear chromatin thickened.Interstitial fibrosis was seen around the tumor.There was no invasion of blood vessels,lymphatic vessels and nerves.Immunohistochemical study exhibited that the tumor cells were focally positive for MOC31 and BreEp4,and strongly positive for CK7,CK5/6,p63,CK34betaE12 and p53.All tumors were negative for CK20,Villin,CDX-2,TTF-1,PSA,P504S and PAX-8.Ki-67 index were 10%approximately.Conclusion Nested variant of urothelial carcinoma with tubule formation is a rare variant of urothelial carcinoma and it is difficult to distinguish this tumor from non-neoplastic lesions of the bladder.The diagnosis depends mainly on the biologically present pattern of irregular infiltration,and immunohistochemical staining can be used as an adjunct to diagnose such lesions.