Department of Pathology, Queen Elizabeth II Health Sciences Center, Nova Scotia Health Authority, Central Zone, Halifax, NS, B3H 1V8, Canada; Dalhousie University, Halifax, NS, B3H 1V8, Canada; Department of Medicine, Queen Elizabeth II Health Sciences Center, Nova Scotia Health Authority, Central Zone, Halifax, NS, B3H 1V8, Canada.
Department of Pathology, Queen Elizabeth II Health Sciences Center, Nova Scotia Health Authority, Central Zone, Halifax, NS, B3H 1V8, Canada; Dalhousie University, Halifax, NS, B3H 1V8, Canada.
Hum Pathol. 2018 Dec;82:232-238. doi: 10.1016/j.humpath.2018.07.022. Epub 2018 Jul 29.
The literature records many examples of Merkel cell carcinoma (MCC) exhibiting aberrant immunohistochemical profiles. These can lead to diagnostic difficulty. The objectives of the current study were (1) to examine the immunohistochemical profile of different subsets of MCC to determine whether predictable subset-specific patterns exist and (2) to establish whether shared immunophenotypic patterns might reveal links between individual subsets, as demonstrated previously at a genetic level. In 52 cases of MCC, stratified by viral status and morphology, we studied 5 markers commonly used in the diagnostic evaluation of these tumors (CK20, CK7, chromogranin, neurofilament and TTF-1). Expression of these proteins was recorded as quantitative (H-scores) and absolute (positive vs negative) variables. In general, our data indicate that the "classical" or expected panel (CK20+, NF+, Chromo+, TTF-1, CK7-) is observed significantly more often in pure Merkel cell polyomavirus (MCPyV)-positive than in MCPyV-negative cases (78% vs 25%; P = .002). Neurofilament was less frequently encountered in MCPyV-negative than in MCPyV-positive tumors (66.7% vs 100%; P = .001) and expression of TTF-1 (37.5% vs 3.6%; P = .003) and CK7 (45.8 vs 14.3; P = .02) was more frequent. No significant immonophenotypic differences were observed between pure and combined MCPyV-negative tumors. Recognition of the more aberrant immunohistochemical profile of MCPyV-negative MCC should inform the diagnostic approach to this tumor. Moreover, the shared aberrant immunophenotype in pure and combined MCPyV-negative tumors supports a link between these entities and serves to separate them from MCPyV-positive tumors.
文献记录了许多 Merkel 细胞癌 (MCC) 表现出异常免疫组织化学特征的例子。这些特征可能导致诊断困难。本研究的目的是：(1) 检查不同 MCC 亚组的免疫组织化学特征，以确定是否存在可预测的亚组特异性模式；(2) 确定是否存在共享的免疫表型模式，以揭示个体亚组之间的联系，如先前在遗传水平上所证明的那样。在按病毒状态和形态分层的 52 例 MCC 中，我们研究了常用于这些肿瘤诊断评估的 5 种标志物 (CK20、CK7、嗜铬粒蛋白、神经丝和 TTF-1)。这些蛋白的表达被记录为定量 (H 评分) 和绝对 (阳性与阴性) 变量。总的来说，我们的数据表明，在纯 Merkel 细胞多瘤病毒 (MCPyV) 阳性病例中，观察到“经典”或预期的标志物 (CK20+、NF+、Chromo+、TTF-1-、CK7-) 的频率明显高于 MCPyV 阴性病例 (78% vs 25%；P =.002)。MCPyV 阴性肿瘤中神经丝的表达频率低于 MCPyV 阳性肿瘤 (66.7% vs 100%；P =.001)，TTF-1 (37.5% vs 3.6%；P =.003) 和 CK7 (45.8% vs 14.3%；P =.02) 的表达频率更高。纯和混合 MCPyV 阴性肿瘤之间未观察到明显的免疫表型差异。认识到 MCPyV 阴性 MCC 更异常的免疫组织化学特征应告知对该肿瘤的诊断方法。此外，纯和混合 MCPyV 阴性肿瘤中共享的异常免疫表型支持这些实体之间的联系，并有助于将它们与 MCPyV 阳性肿瘤区分开来。
