肾集合管癌4例临床及病理特征分析

Clinicopathological characteristics of renal collecting duct carcinoma: an analysis of four cases

目的探讨肾集合管癌的临床病理学特征及其鉴别诊断要点。方法收集4例肾集合管癌患者的临床资料,对手术标本采用HE及免疫组化染色进行病理学观察,同时进行随访,并结合文献复习。结果 4例中男性3例,女性1例;年龄48~76岁;发生于左肾和右肾各2例;临床以血尿、腰痛、消瘦为主要症状;4例均行根治性肾切除术。大体检查4例肿瘤均位于肾髓质,边界不规则,直径4~8.5 cm;镜下见肿瘤细胞呈腺管状或条索状排列,部分呈鞋钉样,细胞核深染,异型性明显,核仁明显,核分裂象多见;间质纤维组织增生明显并伴炎细胞浸润;免疫组化染色显示肿瘤细胞CK7和PAX-8(+),CK20、CK5、p63、GATA-3和S-100(-)。截至随访日期2例已因肿瘤转移而死亡,生存时间为4.5个月和29个月;另2例分别于随访8个月和5个月后失访。结论肾集合管癌是一种少见的肾细胞癌亚型,具高度恶性的生物学行为,预后不良。病理诊断时主要需与内生性浸润性高级别尿路上皮癌相鉴别,明确诊断需依靠仔细检查标本,多取肿瘤与肾盂、肾盏交界处,通过形态学观察有无尿路上皮癌成分来确定,联合使用免疫组化CK7、CK5、p63和CK20染色在二者鉴别时有一定意义。

Objective To study the clinicopathological features and differential diagnosis of renal collecting duct carcinoma. Methods Clinical data were collected in 4 cases of renal collecting duct carcinoma. HE staining and immunohistochemistry were carried out in surgically removed specimen to analyze the clinical and pathological features with review of the literatures. Results The patients aged 48- 76 years,with 3 males and 1 female; the tumor occurred in the left kidney and right kidney in 2 cases respectively; clinical hematuria,low back pain,and weight loss were the main symptoms; Four patients underwent radical nephrectomy. Macroscopically,4 cases of tumors were located in the renal medulla with irregular border,4- 8. 5 cm big in diameter,and taupe and gray on cut surface. Histopathologically,the tumor cells were in tubular and / or streak-like pattern with obvious atypia. The cytoplasm was usually eosinophilic or clear,and the nuclei were large,vesicular,and highly pleomorphic,with prominent single nucleoli,and some of them displayed hobnail-like. Mitoses were numerous,with remarkable interstitially desmoplastic reaction and inflammatory cell infiltration. Immunohistochemical staining showed tumor cells were positive for CK7,PAX-8,and negative for CK20,CK5,p63,GATA-3,S100 P. At the end of the study,2 patients were followed up for 8 months,5 months respectively,and then loss,the remaining 2 patients have died due to tumor metastasis with the survival time 4. 5 and 29 months.Conclusion Renal collecting duct carcinoma is a rare subtype of renal cell carcinoma with a high degree of malignant biological behavior and poor prognosis. Histopathologically it should be differentiated from the endophytic invasive highgrade urothelial carcinoma mainly. It is important to examine specimens carefully,sample the junction of tumor and the renal pelvis / calyces,and microscopically observe in order to determine the presence of urothelial carcinoma or not. A panel consisting of CK7,CK5,P63 and CK20 plays a certain role in differential diagnosis.