Subtyping hepatic adenomas is important for patient management due to differing complication risks. Immunohistochemical staining with C-reactive protein (CRP) and serum amyloid-A (SAA) is widely accepted as a surrogate for molecular classification to identify inflammatory hepatocellular adenomas. Limited data, however, has been published on how these 2 stains compare for sensitivity. We conducted a large, multicenter, retrospective study to examine the sensitivity and staining characteristics of CRP and SAA in inflammatory hepatic adenomas, with focal nodular hyperplasia (FNHs) as a control group. Inflammatory adenomas were identified in 133 patients (average age 37 years, 109 were female). In all, 69.9% of cases were resection specimens and 90.2% of all cases showed positive staining for both CRP and SAA; 10 (7.5%) were positive for CRP only and 3 (2.3%) were positive for SAA only. CRP was more sensitive than SAA (97.74% vs. 92.48%, P -value = 0.0961) and showed more extensive and intense staining, with a significantly higher modified H-score ( P <0.001). Focal nodular hyperplasia can also show positive CRP and SAA staining but with a lower modified H-score ( P <0.0001). Based on beta-catenin and glutamine synthetase staining, 26 of inflammatory adenomas also had beta-catenin activation (19.5%). All 3 cases with positive SAA and negative CRP staining were beta-catenin activated. In contrast, the proportion of cases that were CRP positive and SAA negative was similar regardless of beta-catenin activation. The data affirms the strategy of using both CRP and SAA immunostains for hepatic adenoma subtyping and raises the awareness of the highly variable nature of SAA staining characteristics.

中文翻译：

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CRP 与 SAA 鉴别炎症性肝腺瘤。

由于不同的并发症风险，肝腺瘤的亚型对于患者管理很重要。C反应蛋白（CRP）和血清淀粉样蛋白-A（SAA）的免疫组织化学染色被广泛接受作为分子分类的替代方法来识别炎症性肝细胞腺瘤。然而，关于如何比较这两种染色剂的敏感性的公开数据有限。我们进行了一项大型、多中心、回顾性研究，以检查 CRP 和 SAA 在炎性肝腺瘤中的敏感性和染色特征，并以局灶性结节性增生 (FNH) 作为对照组。133 名患者（平均年龄 37 岁，其中 109 名女性）被发现患有炎性腺瘤。总体而言，69.9%的病例为切除标本，90.2%的病例CRP和SAA均呈阳性染色；10 名（7.5%）仅 CRP 阳性，3 名（2.3%）仅 SAA 阳性。CRP 比 SAA 更敏感（97.74% vs. 92.48%，P 值 = 0.0961），并且显示出更广泛和更强烈的染色，具有显着更高的修正 H 分数（P <0.001）。局灶性结节性增生也可显示 CRP 和 SAA 染色阳性，但修改后的 H 评分较低（P <0.0001）。根据 β-连环蛋白和谷氨酰胺合成酶染色，26 例炎症腺瘤也有 β-连环蛋白激活（19.5%）。3例SAA阳性、CRP染色阴性的病例均被β-连环蛋白激活。相比之下，无论 β-连环蛋白激活如何，CRP 阳性和 SAA 阴性的病例比例相似。这些数据证实了使用 CRP 和 SAA 免疫染色进行肝腺瘤亚型分型的策略，并提高了对 SAA 染色特征的高度可变性的认识。