Department of Pathology, Faculty of Medicine, Zagazig University, Egypt.
Department of Urology, Faculty of Medicine, Zagazig University, Egypt.
Indian J Pathol Microbiol. 2020 Jul-Sep;63(3):405-411. doi: 10.4103/IJPM.IJPM_719_19.
Renal oncocytoma (RO) and chromophobe renal cell carcinoma (ChRCC) originate from the same cell origin, that is, the intercalated cells of the collecting duct. In most cases, there are clear morphologic differences between RO and ChRCC; however, in some instances, overlapping features may be encountered and the differentiation between the two entities becomes difficult. Several immunohistochemical markers with different expression patterns in ChRCC and RO have been described to rule out this dilemma.
About 47 primary renal neoplasms that had been diagnosed as RO or ChRCC were submitted for immunohistochemical staining of amylase α-1A (AMY1A), MOC 31, and CD 82. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy have been analyzed.
AMY1A positivity was observed in all RO cases in our work with 91.7% sensitivity and 100% specificity in the diagnosis of RO. The PPV of its expression was (100%) and NPV (97.2%) with a diagnostic accuracy of 97.9%. A significant high expression of MOC 31 was observed in ChRCC compared to its expression in RO with a statistical significance (P < 0.001). In addition, we obtained 82.9% sensitivity and 91.7% specificity of MOC 31 expression in the diagnosis of ChRCC. The positive predictive value (PPV) was (96.7%), negative predictive value (NPV) (64.7%) with diagnostic accuracy (85.1%). In our studied cases, we detected positive immunoexpression of CD 82 in 10 cases (83.3%) of ChRCC. However, it was lost in all RO cases (100%). CD 82 sensitivity and specificity in differentiating ChRCC from RO were 100% and 83.3%, respectively.
We propose MOC 31 and CD 82 as negative immunostains for RO, as these markers are commonly expressed in ChRCC. In conjunction with AMY1A strong immunopositivity in RO cases, we provide a triple panel of biomarkers (AMY1A, MOC 31, and CD 82) for the distinction between RO and ChRCC.
肾嗜酸细胞瘤（RO）和嫌色细胞肾细胞癌（ChRCC）起源于同一细胞起源，即集合管的闰细胞。在大多数情况下，RO 和 ChRCC 之间存在明显的形态学差异；然而，在某些情况下，可能会出现重叠特征，使得两者难以区分。已经描述了几种在 ChRCC 和 RO 中具有不同表达模式的免疫组织化学标志物，以排除这种困境。
大约 47 例被诊断为 RO 或 ChRCC 的原发性肾肿瘤被提交进行淀粉酶 α-1A（AMY1A）、MOC 31 和 CD 82 的免疫组织化学染色。分析了敏感性、特异性、阳性预测值（PPV）、阴性预测值（NPV）和诊断准确性。
在我们的研究中，所有 RO 病例均表现出 AMY1A 阳性，诊断 RO 的敏感性为 91.7%，特异性为 100%。其表达的阳性预测值（PPV）为（100%），阴性预测值（NPV）为（97.2%），诊断准确性为 97.9%。与 RO 相比，ChRCC 中 MOC 31 的表达显著升高，具有统计学意义（P < 0.001）。此外，我们在 ChRCC 的诊断中获得了 82.9%的敏感性和 91.7%的特异性。阳性预测值（PPV）为（96.7%），阴性预测值（NPV）为（64.7%），诊断准确性为（85.1%）。在我们研究的病例中，我们在 10 例（83.3%）ChRCC 中检测到 CD 82 的阳性免疫表达。然而，在所有 RO 病例中（100%）均丢失。CD 82 在区分 RO 和 ChRCC 方面的敏感性和特异性分别为 100%和 83.3%。
我们提出 MOC 31 和 CD 82 作为 RO 的阴性免疫标记物，因为这些标记物在 ChRCC 中通常表达。结合 RO 病例中 AMY1A 的强免疫阳性，我们提供了一个用于区分 RO 和 ChRCC 的三重生物标志物（AMY1A、MOC 31 和 CD 82）。
