Yeni Erdem Begum, Baykal Can, Ozluk Yasemin, Ahmed Melin A, Kozanoglu Erol, Saip Pinar, Buyukbabani Nesimi, Ozturk Sari Sule
Department of Pathology, Istanbul Faculty of Medicine, Istanbul University, Millet Caddesi, Fatih, Istanbul, 34093, Turkey.
Department of Dermatology and Venereology, Istanbul Faculty of Medicine, Istanbul University, Millet Caddesi, Fatih, Istanbul, 34093, Turkey.
Endocr Pathol. 2025 Jan 22;36(1):1. doi: 10.1007/s12022-024-09845-w.
Merkel cell carcinoma (MCC) is diagnosed through histopathological and immunohistochemical examination of biopsies from skin or other organs. Its distinguishing features include perinuclear dot-like staining with Cytokeratin 20 (CK20) and detection of Merkel cell polyomavirus (MCPyV) using various methods. However, CK20 and MCPyV negative MCC cases have been reported at varying rates. In this single center cross-sectional study, we aimed to determine which clones are more effective in diagnosing MCC by comparing the performance of CK20 antibody clones Ks20.8 and SP33, as well as MCPyV antibody clones Ab3 and CM2B4. Fifty-four patients diagnosed with MCC were included. Among these, 42 cases were primary cutaneous, and 12 cases were nodal MCC. Fifty-two (96.3%) cases were positive with both CK20 clones, while two cases were negative. Clone SP33 stained areas of necrosis, whereas Ks20.8 showed no aberrant staining. MCPyV was detected in 44 cases (81.5%) using clone Ab3 and 39 cases (72.2%) using clone CM2B4. Staining with MCPyV clone Ab3 was diffuse and strong in most cases, while approximately 30% of CM2B4-positive cases exhibited low percentages and/or weak staining, complicating the evaluation. The two CK20-negative cases were also negative with both MCPyV clones. Our data demonstrated that CK20 clone Ks20.8 may be preferred for MCC diagnosis due to its consistent performance and lack of aberrant staining. Similarly, MCPyV clone Ab3 appears superior to CM2B4 for identifying MCPyV-positive cases.
默克尔细胞癌（MCC）通过对皮肤或其他器官活检组织进行组织病理学和免疫组织化学检查来诊断。其显著特征包括细胞角蛋白20（CK20）呈核周点状染色，以及使用多种方法检测默克尔细胞多瘤病毒（MCPyV）。然而，已有不同比例的CK20和MCPyV阴性的MCC病例报道。在这项单中心横断面研究中，我们旨在通过比较CK20抗体克隆Ks20.8和SP33以及MCPyV抗体克隆Ab3和CM2B4的性能，确定哪些克隆在诊断MCC方面更有效。纳入了54例诊断为MCC的患者。其中，42例为原发性皮肤MCC，12例为淋巴结MCC。52例（96.3%）病例的两个CK20克隆均呈阳性，2例为阴性。克隆SP33对坏死区域染色，而Ks20.8未显示异常染色。使用克隆Ab3检测到44例（81.5%）MCPyV阳性，使用克隆CM2B4检测到39例（72.2%）阳性。大多数情况下，MCPyV克隆Ab3染色弥漫且强，而约30%的CM2B4阳性病例显示阳性率低和/或染色弱，使评估复杂化。2例CK20阴性病例的两个MCPyV克隆也均为阴性。我们的数据表明，CK20克隆Ks20.8因其性能一致且无异常染色，可能更适合用于MCC诊断。同样，MCPyV克隆Ab3在识别MCPyV阳性病例方面似乎优于CM2B4。
