透明细胞乳头状肾细胞癌的临床病理分析

Clinicopathological analysis of clear cell papillary renal cell carcinoma

目的探讨透明细胞乳头状肾细胞癌(clear cell papillary renal cell carcinoma,CCPRCC)的临床病理学特征、免疫表型、鉴别诊断及预后。方法收集2013年至2017年肾细胞癌病理切片,筛选CCPRCC 4例,收集临床资料并研究组织病理学形态及免疫组织化学特征。结果患者年龄在46岁至69岁之间(平均55.3岁),男性1例,女性3例;影像学资料显示,肿瘤平均直径为3.85 cm(1.6~7.0cm),所有肿瘤均为右肾单发肿物。4例均呈大小不等的类圆形单结节,CT显示为低密度,MRI显示为低信号。大体观察肿瘤局限于肾组织内呈单结节状生长,境界清楚,局部似带包膜,切面呈灰红至灰褐色,实性,质地中等,部分区稍韧,局灶伴有出血或囊性变。镜下见肿瘤细胞排列呈囊状、乳头状、管状/腺泡状和实性巢状结构,细胞核形态温和,远离基底膜并朝向腔面,本组病例均为WHO/ISUP分级Ⅰ-Ⅱ级,间质内可见散在数量不等的平滑肌组织。CA-9及CK7免疫组织化学染色阳性,TFE3、vimentin、CD10与AMACR阴性或局灶弱阳性。1例行FISH检测TFE3未见检测出基因相关易位。随访1~4年,均无复发及转移。结论CCPRCC的病理诊断主要依据独特的形态和免疫表型特征。CCPRCC是一种相对惰性的肿瘤,正确的诊断对临床治疗和预后具有重要意义。

Objective To investigate the clinicalpathological features, immunohistochemical phenotypes, differential diagnosis of clear cell papillary renal cell carcinoma( CCPRCC) and their correlation with prognosis. Methods 4 cases of CCPRCC with follow-up retrieved from in-house files(between January 2013 to December 2017) were analyzed with emphasis on clinicalpathological features, immunohistochemical phenotypes and the prognostic impact. Results Patients ranged in age from 46 to 69 years(mean 55.3 years), among which there was 1 male and 3 female patients. Imaging data showed that the average diameter of the tumors was 3.85 cm(1.6-7.0 cm). All 4 cases showed single tumor located in various sites of right kidney. All the 4 patients presented single roundlike nodules of different sizes, with low density in CT image and low signal in MRI image. Gross observation showed that the tumor was confined to the renal tissue and showed single nodular growth, with clear boundary, local capsule, grayish-red to grayish-brown section, solid, medium texture with some slightly tough areas, focal lesions accompanied by bleeding or cystic changes. Histologically, CCPRCC cells were arranged in a wide range of architectural components including cystic, papillary, tubulous/acinar and solid nests. The nuclei showed mild morphological changes, polarized away from the basement membrane and faced the lumen surface. All the 4 cases were classified into WHO/ISUP Grade Ⅰ-Ⅱ. The tumor mesenchymal tissues contained a varying amount of smooth muscle tissues. The immunohistochemical staining showed CK7 and CA-9 were positive in all cases while TFE3, vimentin, CD10 and AMACR were negative or focal weak positive. FISH test was conducted in one case, in which TFE3 gene-related translocation was not detected. The patients were followed up for 1~4 years, and none of them had recurrence or metastasis. Conclusion The pathological diagnosis of CCPRCC is mainly on the basis of its specific morphology and immunohistochemistry manifestations. CCPRCC is a relatively inert tumor. Correct diagnosis is of great significance for clinical treatment and prognosis.