管状囊性肾细胞癌1例临床病理观察

Tubulocystic renal cell carcinoma:a clinicopathologic analysis of one case

目的探讨管状囊性肾细胞癌(TRCC)的临床病理学特征及鉴别诊断要点。方法收集1例管状囊性肾细胞癌临床资料、观察其病理学形态及免疫表型,并复习相关文献,探讨该肿瘤的病理诊断和鉴别诊断要点。结果患者女性,27岁,体检发现左肾占位2周。镜下观察肿瘤边界清楚,可见纤细的纤维性间质分隔的大小不等的囊状和小管状结构,囊腔内含黏液蛋白样物质,囊腔内衬覆扁平或柱状上皮细胞、"鞋钉样"细胞。细胞核圆形或卵圆形,空泡状,核仁可见,WHO/ISUP 3级,核分裂象不易见,胞质丰富,嗜酸性。免疫表型:瘤细胞表达CK、CK19、PAX-8、vimentin、P504S;Ki-67核阳性比例8%。结论管状囊性肾细胞癌是一种罕见的肿瘤,主要发生于老年患者,大部分患者预后好,需与管状囊性结构特征的肿瘤鉴别,其确诊需结合组织病理学及免疫组化表型,必要时结合分子遗传学改变。

Objective To investigate clinicopathologic features and differential diagnosis of tubulocystic renal cell carcinoma(TRCC). Methods The clinical data of a case of TRCC were collected and its pathological and immunohistochemical features analyzed for the pathological diagnosis and differential diagnosis based on related literature review. Results The age of the patient at diagnosis was 27 year and female. The lesion was located in the left kidney, found by physical examination. Grossly, tumour presented as a well-circumscribed multicystic renal mass, 6.5 cm in diameter. Histopathologically, the tumour was composed of small to intermediate-sized tubules admixed with larger cysts, which were lined by a single layer of flattened, cuboidal/columnar, and hobnail epithelial cells. The nuclei were enlarged and irregular, with intermediate to large nucleoli(WHO/International Society of Urological Pathology grade 3). Cytoplasmic features included abundant eosinophilic cytoplasm. The stroma was fibrotic, and the mitoses were infrequent. Immunophenotyping showed that the tumour cells demonstrated immunopositivity for pancytokeratin, vimentin, CK19 and P504 s and were negative for CK7. The positive rate of the Ki-67 was 8%. Conclusion TRCC is a rare tumor, mainly occurs in elderly patients;most of them have a favorable prognosis. Differential diagnosis includes other renal neoplasms in a tubulocystic growth pattern. The diagnosis should be combined with histopathological and immunohistochemical phenotype and molecular genetic aberration.