肾脏混合性上皮间质肿瘤

Mixed epithelial and stromal tumor of kidney

目的探讨肾脏混合性上皮间质肿瘤的临床病理特征。方法观察4例肾脏混合性上皮间质肿瘤的临床资料、镜下及免疫组织化学特点。结果患者3例女性,1例男性。临床表现主要为腰部不适和血尿,影像学检查示肾脏囊实性占位性病变。病理检查:肉眼肿瘤呈囊实性结构,镜下肿瘤由上皮和间质成分共同构成。上皮细胞可呈立方状、柱状、鞋钉样;其中1例上皮成分呈苗勒管上皮分化和肠上皮分化。间质成分为梭形细胞,并可见特征性呈束状分布的平滑肌组织和厚壁血管。免疫组织化学:上皮细胞AE1/AE3阳性,间质细胞雌激素受体(ER)、孕激素受体(PR)、平滑肌肌动蛋白(SMA)阳性。患者行肾切除术,术后随访未见复发。结论肾脏混合性上皮间质肿瘤为具有独特组织病理学特点的良性肿瘤,需要和肾脏其他良恶性肿瘤鉴别。

Objective To study the clinicopathological features and differential diagnoses of mixed epithelial and stromal tumor of the kidney. Methods Clinical and pathological characteristics of 4 cases of mixed epithelial and stromal tumor of the kidney were studied. Results Three patients were female and one was male. All patients presented with flank pain and hematuria. Radiologic studies revealed cystic and solid masses involving the kidney. Grossly the tumors had a solid and cyst appearance. Microscopically, the tumors were composed of a mixture of stromal and epithelial elements. The epithelial elements were variable in cell types including cuboidal, hobnail and columnar cells. One case showed Mullerian and intestinal epithelial differentiations. Stromal elements essentially consisted of spindle cells, with thick-walled blood vessels and bands of smooth muscle cells as distinctive features of the tumor. Immunohistochemical staining revealed that the epithelial components were positive for AE1/AE3, whereas the stromal components were positive for ER, PR, and SMA. All patients underwent nephrectomy and were well without evidence of recurrence. Conclusions Mixed epithelial and stromal tumor of the kidney is a benign neoplasm with distinct histopathological features. It should be distinguished from many other renal neoplasms. Surgical intervention is a preferred therapy.