Department of Pathology, The Ohio State University Medical Center, 410 W 10th Ave., 401 Doan Hall, Columbus, OH, 43210, USA.
Diagn Pathol. 2019 Aug 16;14(1):91. doi: 10.1186/s13000-019-0871-8.
Urothelial carcinoma in situ (CIS) in the bladder can be difficult to diagnose due to factors including procedural artifact, minimal tissue sampled, therapy-related changes, and various CIS growth patterns. Prior data has demonstrated an increase in alpha-methylacyl-CoA-racemase (AMACR) in urothelial CIS, but there is no information on its utility for diagnosing difficult cases. The aim of this investigation was to assess the expression of AMACR that was ordered on equivocal bladder cases during clinical practice.
Transurethral resections of the bladder in which AMACR and CK20 were performed during diagnostic workup were identified and cases with a final diagnosis of CIS (n = 22) or non-neoplastic urothelium (n = 30) were selected. Additionally, cases in which a diagnosis of CIS was rendered without IHC (n = 20) were selected and tested for AMACR expression.
Sensitivity of AMACR for CIS diagnosed with IHC during clinical practice was 73% and specificity was 97%, while CK20 was 95% sensitive and 80% specific. Sensitivity of AMACR in CIS diagnosed without IHC was 100%. In all groups, AMACR had inconsistent intensity, compared to CK20 which had consistent, strong intensity.
AMACR was usually positive in urothelial CIS and negative in non-neoplastic urothelium. However, it is important to note that AMACR was less sensitive in difficult cases, while CK20 was more sensitive with more consistent, strong staining compared to AMACR.
由于程序伪影、采样组织较少、治疗相关变化以及各种 CIS 生长模式等因素，膀胱原位尿路上皮癌（CIS）的诊断较为困难。先前的数据表明，尿路上皮 CIS 中的α-甲基酰基辅酶 A-消旋酶（AMACR）增加，但尚无关于其用于诊断困难病例的信息。本研究旨在评估在临床实践中对疑似膀胱病例进行 AMACR 检测的结果。
确定在诊断性膀胱检查中进行 AMACR 和 CK20 检测的经尿道膀胱切除术，并选择最终诊断为 CIS（n=22）或非肿瘤性尿路上皮（n=30）的病例。此外，选择了未进行免疫组化（IHC）但诊断为 CIS 的病例，并检测其 AMACR 表达。
在临床实践中通过 IHC 诊断 CIS 时，AMACR 的敏感性为 73%，特异性为 97%，而 CK20 的敏感性为 95%，特异性为 80%。未进行 IHC 诊断 CIS 时，AMACR 的敏感性为 100%。在所有组中，与 CK20 具有一致、强烈的强度相比，AMACR 的强度不一致。
AMACR 在尿路上皮 CIS 中通常为阳性，在非肿瘤性尿路上皮中为阴性。然而，值得注意的是，在困难病例中 AMACR 的敏感性较低，而 CK20 的敏感性更高，且染色更一致、强烈。
