Slater M, Barden J A
School of Biomedical Sciences, Department of Anatomy and Histology, The University of Sydney, Sydney, NSW 2006, Australia.
Histopathology. 2005 Aug;47(2):170-8. doi: 10.1111/j.1365-2559.2005.02155.x.
Keratoacanthomas (KA) are well-differentiated squamoproliferative skin lesions that grow rapidly and regress spontaneously. In contrast, squamous cell carcinomas (SCC) can have variable differentiation, inexorably progress and on occasion metastasize. Distinguishing between KA and SCC using haematoxylin and eosin-stained sections from an initial biopsy can often be difficult. There is also some debate as to whether KA is simply a variety of well-differentiated SCC or a distinct entity.
Initial biopsy sections from 25 cases of SCC and 20 of KA were labelled with markers for both the initiation (the cytolytic receptor P2X7) and end-stage (terminal deoxynucleotidyl transferase biotin-dUTP nick end labelling) of apoptosis, telomerase-associated protein (TP1) and the cell adhesion protein E-cadherin. As this was a retrospective study, the clinical outcome of each case was known. This resulted in a unique labelling pattern of each marker for SCC and KA, allowing a differential diagnosis between the two conditions. The simplest marker to use for this purpose was anti-P2X7. Sections from five cases that were initially very difficult to diagnose were correctly identified as SCC using this method.
These results support the view that KA has a different pathogenesis and biochemistry from that of SCC, and is a distinct entity. Anti-P2X7 labelling, using routine immunohistochemical techniques, provides a method for differentially diagnosing these conditions.
角化棘皮瘤（KA）是分化良好的鳞状上皮增生性皮肤病变，生长迅速且可自发消退。相比之下，鳞状细胞癌（SCC）的分化程度各异，会持续进展，偶尔还会发生转移。利用苏木精和伊红染色的初始活检切片区分KA和SCC往往很困难。关于KA究竟只是一种分化良好的SCC还是一个独立的实体也存在一些争议。
对25例SCC和20例KA的初始活检切片用凋亡起始（溶细胞受体P2X7）和终末期（末端脱氧核苷酸转移酶生物素-dUTP缺口末端标记）、端粒酶相关蛋白（TP1）以及细胞黏附蛋白E-钙黏蛋白的标志物进行标记。由于这是一项回顾性研究，每例病例的临床结果是已知的。这导致了SCC和KA每种标志物独特的标记模式，从而能够对这两种情况进行鉴别诊断。用于此目的最简单的标志物是抗P2X7。最初很难诊断的5例病例的切片用这种方法被正确鉴定为SCC。
这些结果支持KA与SCC具有不同的发病机制和生物化学，且是一个独立实体的观点。使用常规免疫组织化学技术进行抗P2X7标记提供了一种鉴别诊断这些情况的方法。
