Sun Belinda L, Abern Michael, Garzon Steven, Setty Suman
Department of Pathology, University of Illinois Hospital & Health Sciences System, Chicago, IL, USA.
Department of surgery, University of Illinois Hospital & Health Sciences System, Chicago, IL, USA.
Int J Surg Pathol. 2015 May;23(3):238-42. doi: 10.1177/1066896914563391. Epub 2014 Dec 18.
Cystic nephroma (CN) is a rare, benign, renal neoplasm composed of epithelial and stromal elements. Only about 200 cases have been reported since 1892 and recurrence has rarely been observed. We report a 32-year-old Hispanic woman, with a history of a right, complex cystic, renal mass treated by robotic decortication 2 years ago, who presented with flank pain, hematuria, and recurrent urinary tract infection. A magnetic resonance imaging study showed a 3.4-cm multicystic lesion with thickened septa and enhancement at the right kidney. The partial nephrectomy specimen revealed a well-circumscribed, multicystic tumor abutting the renal pelvis, with thick septa and smooth walls, filled with clear fluid. Microscopic examination showed variably sized cysts lined by cuboidal epithelium with focal hobnailing, without significant cytologic atypia and mitosis. The epithelial lining was positive for CK19, high molecular weight cytokeratin, and α-methylacyl-CoA racemase suggesting a primitive tubular epithelial phenotype. Primitive glomeruli-like structures were also present. The ovarian-like stroma was condensed around the cysts and was variably cellular with areas of muscle differentiation and thick-walled vessels. The stroma was positive for desmin, estrogen receptor, progesterone receptor, and CD10. We suggest that CN represents a variable mixture of epithelial and stromal elements, immature glomerular, tubular, muscle, and vascular elements, which may be present in variable proportions creating a spectrum of lesions previously described as CN and mixed epithelial and stromal tumors (MEST). This case emphasizes that CN/MEST clinically/radiologically mimics other cystic renal neoplasms, especially cystic renal cell carcinoma and tubulocystic carcinoma, necessitating histopathological examination and immunohistochemial studies for definitive diagnosis. Additionally, CN has the tendency to recur when not completely excised initially.
囊性肾瘤（CN）是一种罕见的良性肾肿瘤，由上皮和间质成分组成。自1892年以来，仅报道了约200例病例，很少观察到复发情况。我们报告了一名32岁的西班牙裔女性，2年前因右侧复杂性囊性肾肿块接受了机器人去皮质术治疗，此次因胁腹痛、血尿和反复尿路感染前来就诊。磁共振成像研究显示右肾有一个3.4厘米的多囊性病变，伴有增厚的间隔且有强化。部分肾切除术标本显示一个边界清晰的多囊性肿瘤，毗邻肾盂，有厚间隔和平滑壁，充满清亮液体。显微镜检查显示大小不一的囊肿内衬立方形上皮，有局灶性鞋钉样改变，无明显细胞学异型性和核分裂象。上皮衬里CK19、高分子量细胞角蛋白和α -甲基酰基辅酶A消旋酶呈阳性，提示为原始肾小管上皮表型。还存在原始肾小球样结构。卵巢样间质在囊肿周围浓缩，细胞成分不一，有肌肉分化区域和厚壁血管。间质结蛋白、雌激素受体、孕激素受体和CD10呈阳性。我们认为CN代表上皮和间质成分、未成熟肾小球、肾小管、肌肉和血管成分的可变混合，这些成分可能以不同比例存在，形成了先前描述为CN和混合上皮和间质肿瘤（MEST）的一系列病变。该病例强调CN/MEST在临床/放射学上可模仿其他囊性肾肿瘤，尤其是囊性肾细胞癌和肾小管囊性癌，因此需要进行组织病理学检查和免疫组化研究以明确诊断。此外，CN如果最初未完全切除有复发倾向。
