鳞状上皮角化瘤(KA)被广泛认为是一种良性、通常可自愈的肿瘤，与皮肤鳞状细胞癌（cSCC）有所不同，而有些人认为KA与cSCC无法区分开。出版的研究表明，p16、p53、Ki-67免疫染色和弹性van Gieson（EVG）在评估KA和cSCC方面具有实用性。我们比较了完全切除的KA、具有KA样特征的cSCC（cSCC-KAL）和其他cSCC（cSCC-OTHER）的临床特征和p16、p53、Ki-67和EVG的染色模式。发现KA、cSCC-KAL和cSCC-OTHER之间在头颈部位置（20%、86%、84%）和持续时间<5个月（95%、63%、36%）方面存在显著差异。KA显示出p16的马赛克样模式（＞25-90%的肿瘤区域）和p53的外周分级模式（高达50%的中等和强核染色），在92%的病例中，而在cSCC-KAL和cSCC-OTHER中为0%。相反，KA中不存在p16和/或p53的高度异常模式（通常为零），而在cSCC-KAL的83.8%和cSCC-OTHER的90.9%中存在这种模式。KA中，Ki-67的异常分布超出外周1-3个细胞是罕见的（4.2%），而在cSCC-KAL（67.6%）和cSCC-OTHER（88.4%）中则很常见。大多数KA（84%）、cSCC-KAL（81%）和cSCC-OTHER（65%）存在中度到显著的弹性和胶原纤维梗阻。KA是临床上明显不同的肿瘤，通常持续时间短，首选发生在头颈部以外的部位，一般不具有p16、p53和Ki-67的异常变异，而cSCC具有高比例的p16、p53和Ki-67异常变异或高度异常变异，但EVG缺乏特异性。版权所有 © 2023 Elsevier B.V. 发布。

Keratoacanthoma (KA) is widely considered a benign, usually self-resolving, neoplasm distinct from cutaneous squamous cell carcinoma (cSCC), while some consider KA to be indistinguishable from cSCC. Published studies indicate utility for p16, p53, Ki-67 immunostaining and elastic van Gieson (EVG) in the assessment of KA and cSCC. We compared clinical features and staining patterns for p16, p53, Ki-67 and EVG in fully excised KA, cSCC with KA-like features (cSCC-KAL) and other cSCC (cSCC-OTHER). Significant differences between KA, cSCC-KAL and cSCC-OTHER were found for head and neck location (20%, 86%, 84%), and duration <5 months (95%, 63%, 36%). KA shows both a mosaic pattern for p16 (>25-90% of neoplasm area) and peripheral graded pattern for p53 (up to 50% moderate and strong nuclear staining) in 92% compared with 0% of cSCC-KAL and 0% of cSCC-OTHER. In contrast, a highly aberrant pattern (usually null) for one or both p16 and p53, was present in 0% of KA, 83.8% of cSCC-KAL and 90.9% of cSCC-OTHER. Abnormal distribution of Ki-67 beyond the peripheral 1-3 cells was uncommon in KA (4.2%) and common in cSCC-KAL (67.6%) and cSCC-OTHER (88.4%). Moderate to striking entrapment of elastic and collagen fibres was present in the majority of KA (84%), cSCC-KAL (81%) and cSCC-OTHER (65%). KA are clinically distinct neoplasms typically of short duration occurring preferentially outside the head and neck and generally lacking aberrations of p16, p53 and Ki-67, compared with cSCC that have high rates of aberrant or highly aberrant p16, p53 and Ki-67, but EVG lacked specificity.Copyright © 2023. Published by Elsevier B.V.