Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
Am J Surg Pathol. 2012 Oct;36(10):1425-33. doi: 10.1097/PAS.0b013e31825b37f0.
Multilocular cystic renal cell carcinoma (RCC) is an uncommon renal neoplasm composed of thin fibrous septa lining multiple cystic spaces and associated with an excellent prognosis. Clear cells with generally low-grade nuclear features line the cystic spaces and may be present within the fibrous septa, although solid mass-forming areas are by definition absent. Despite the excellent prognosis, molecular-genetic alterations are similar to those of clear cell RCC. Immunohistochemical staining characteristics, however, have not been well elucidated. We studied 24 cases of multilocular cystic RCC, classified according to the 2004 World Health Organization System. Immunohistochemical analysis was performed using an automated immunostainer for CD10, cytokeratin 7 (CK7), α-methylacyl-CoA-racemase, epithelial membrane antigen (EMA), cytokeratin CAM 5.2, carbonic anhydrase IX (CA-IX), estrogen/progesterone receptors, smooth muscle actin, PAX-2, and vimentin. Twenty-four cases of grade 1 to 2 clear cell RCC were stained for comparison. Multilocular cystic RCC and control cases of clear cell RCC showed the following results, respectively: CD10 (63%, 96%), CK7 (92%, 38%), α-methylacyl-CoA-racemase (21%, 67%), vimentin (58%, 33%), estrogen receptor (8%, 8%), CAM 5.2 (100%, 96%), EMA, CA-IX, PAX-2 (all 100%), and progesterone receptor (0%). Smooth muscle actin highlighted myofibroblastic cells within the septa of multilocular cystic RCC and the fine capillary vascular network of clear cell RCC. In summary, multilocular cystic RCC showed expression of common clear cell RCC markers CA-IX, EMA, and PAX-2, supporting the hypothesis that multilocular cystic RCC is a subtype of clear cell RCC. In contrast to clear cell RCC, tumors less frequently expressed CD10 (63% and often focal vs. 96% and diffuse) and more frequently expressed CK7 (92%), often diffusely (63%). Coexpression of CA-IX and CK7 represents a point of overlap with the recently described clear cell papillary RCC, which also may show a prominent cystic architecture. However, the latter lacks mutation of the VHL gene and deletion of chromosome 3p by molecular methodologies.
多房囊性肾细胞癌（RCC）是一种罕见的肾肿瘤，由薄纤维隔衬里的多个囊性空间组成，预后良好。囊腔由具有一般低级别核特征的透明细胞构成，可能存在于纤维隔内，尽管定义上不存在实性肿块形成区。尽管预后良好，但分子遗传改变与透明细胞 RCC 相似。然而，免疫组织化学染色特征尚未得到充分阐明。我们研究了 24 例多房囊性 RCC，根据 2004 年世界卫生组织系统进行分类。使用自动化免疫染色仪对 CD10、细胞角蛋白 7（CK7）、α-甲基酰基辅酶 A 消旋酶、上皮膜抗原（EMA）、细胞角蛋白 CAM5.2、碳酸酐酶 IX（CA-IX）、雌激素/孕激素受体、平滑肌肌动蛋白、PAX-2 和波形蛋白进行免疫组织化学分析。为了比较，对 24 例 1 级至 2 级透明细胞 RCC 进行了染色。多房囊性 RCC 和对照的透明细胞 RCC 病例分别显示以下结果：CD10（63%，96%）、CK7（92%，38%）、α-甲基酰基辅酶 A 消旋酶（21%，67%）、波形蛋白（58%，33%）、雌激素受体（8%，8%）、CAM5.2（100%，96%）、EMA、CA-IX、PAX-2（均为 100%）和孕激素受体（0%）。平滑肌肌动蛋白突出了多房囊性 RCC 纤维隔中的肌纤维母细胞和透明细胞 RCC 的精细毛细血管网络。总之，多房囊性 RCC 表达常见的透明细胞 RCC 标志物 CA-IX、EMA 和 PAX-2，支持多房囊性 RCC 是透明细胞 RCC 亚型的假说。与透明细胞 RCC 相比，肿瘤较少表达 CD10（63%且通常为局灶性，而非 96%且弥漫性），更常表达 CK7（92%，通常弥漫性）。CA-IX 和 CK7 的共表达代表与最近描述的透明细胞乳头状 RCC 的一个重叠点，后者也可能表现出突出的囊性结构。然而，后者缺乏 VHL 基因突变和染色体 3p 缺失，这是通过分子方法确定的。
