低度恶性潜能多房性囊性肾肿瘤的临床病理分析

Clinical and pathological analysis of multilocular cystic renal neoplasm of low malignant potential

目的:探讨低度恶性潜能多房性囊性肾肿瘤的临床病理特点及与其他囊性肾疾病的诊断和鉴别。方法:收集21例低度恶性潜能多房性囊性肾肿瘤患者的临床及病理资料,对其行组织形态学观察和免疫组织化学分析。结果:患者男14例,女7例;年龄22~61岁,平均43岁。13例常规体检发现,其余8例因腰部不适或血尿入院。大体检查:肿瘤直径1.5~4.2cm,界限清楚。切面呈多房囊性或蜂窝状,囊内含清亮浆液性或凝胶状液体。显微镜下囊壁衬覆单层胞浆透亮的肿瘤细胞,细胞核小,未见核仁,WHO/ISUP核分级1级17例,2级4例;衬覆细胞偶可见呈多层,或形成囊内小乳头。囊壁由薄层纤维组织构成,3例伴钙化。囊壁间可见呈簇或小巢状分布的肿瘤细胞。免疫组化显示:肿瘤细胞PAX8和CAⅨ呈强阳性,CK、CK7、上皮膜抗原(EMA)和波形蛋白(Vimentin)部分阳性,而CD10阳性仅3例。7例行根治性肾切除术,14例行肾部分切除术。19例术后获随访,随访时间7~216个月,均未见复发和转移。结论:低度恶性潜能多房性囊性肾肿瘤是2016版WHO泌尿系统和男性生殖系统肿瘤分类新更名的一个肾肿瘤,其WHO/ISUP核分级低、低TNM临床分期,预后极好,诊断时需严格把握标准。临床上需依据肿瘤部位、大小以及有无突破肾包膜等决定手术方式。

Objective：To investigate the clinical and pathological characteristics of multilocular cystic renal neoplasm of low malignant potential,its diagnosis and differential diagnosis from other cystic renal diseases.Method：Twenty-one cases with multilocular cystic renal neoplasm of low malignant potential were studied by clinical data,pathological features and immunophenotype.Result：The patients＇ age ranged from 22 to 61（mean,43）years old,with a male to female ratio of 2∶1.Thirteen cases were incidentally discovered by radiological checkup,and 8 of them presented with haematuria or discomfort in the waist.Macroscopically,the tumor ranged from 1.5 to 4.2 cm in diameter,which consisted of various sized cysts separated by thin septa and filled with clear,serous or gelatinous fluid.Microscopically,most cysts were lined by a single layer of tumor cells with abundant clear cytoplasm and small nuclei without nucleoli（WHO/ISUP grade 1 in 17 cases and grade 2 in 4 ones）.Multilayered tumor cells could be seen in some cysts,and even small intracystic papillations.The septa consisted of thin fibrous tissue with calcification occasionally.Clusters of tumor cells presented within the fibrous septa that were similar to those lining the cysts.Immunohistochemical staining displayed that tumor cells showed strong positive for PAX8 and CAIX,partly positive for CK,CK7,EMA and vimentin,and only 3 cases showed positive for CD10.Seven patients underwent radical nephrectomy while the other 14 cases received nephron sparing surgery.After 7 to 216 months of follow-up period,19 patients showed no evidence of recurrence or metastasis.Conclusion：Multilocular cystic renal neoplasm of low malignant potential is a new tumor entity that was renamed in the 2016 WHO Classification of Tumours of the Urinary System and Male Genital Organs,with low WHO/ISUP grade,low TNM stage and good prognosis.It should be treated by various surgical resection according to the tumor location,size and capsule invasion or not.