Abstract：
Diagnosis of basal cell carcinoma (BCC) higher risk subtypes influences management strategies because of their propensity to recur locally. Subtyping is prone to inter-observer variability, and subtyping definitions are inconsistently applied. This study sought to compare the interobserver reproducibility of individual BCC subtypes using the 4th edition World Health Organization (WHO) Classification of Skin Tumours (CoST) definitions, with classification into lower and higher risk histological subtype groups. Ninety-one BCC cases were rated by seven pathologists, noting the presence of BCC subtype(s), and providing a higher or lower risk subtype grouping per case. Raters were provided with definitions as per the 4th edition WHO CoST for 10 listed BCC subtypes. Surgical specimen type was noted. Subgroup analysis was performed to exclude cases when the tumour deep front was not well visualised, or there was tangential sectioning (n = 6). Light\'s kappa was used to assess inter-rater reliability. From the total group (n = 91), five BCC subtypes showed a sufficient number of ratings for computing a κ statistic. From these five subtypes, superficial subtype showed substantial inter-rater agreement (κ = 0.64), and the other four subtypes showed moderate inter-rater agreement [nodular (κ = 0.45), sclerosing/morphoeic (κ = 0.45), infiltrating (κ = 0.49) and micronodular (κ = 0.57)]. Two-tiered rating into either higher or lower risk subtype showed substantial inter-rater agreement (κ = 0.72). Our results suggest a need to more precisely define BCC subtypes. We suggest reporting BCC subtype using a two-tiered risk grouping, followed by specific subtypes present. Further studies examining the inter-rater reliability of less common BCC subtypes are required.
摘要：
基底细胞癌（BCC）高风险亚型的诊断会影响管理策略，因为它们倾向于局部复发。亚型容易出现观察者间的变异性，和子类型定义的应用不一致。本研究旨在使用第4版世界卫生组织（WHO）皮肤肿瘤分类（CoST）定义比较单个BCC亚型的观察者间可重复性。分为风险较低和较高的组织学亚型组。七位病理学家对91例BCC病例进行了评估，注意到BCC亚型的存在，并为每个病例提供较高或较低风险的亚型分组。根据第4版WHOCoST，为评估者提供了10种列出的BCC亚型的定义。注意手术标本类型。进行亚组分析以排除肿瘤深前缘没有很好可视化的病例。或者有切向切片(n=6)。使用LightKappa评估者间的可靠性。从总组(n=91)来看，五种BCC亚型显示出足够数量的评级来计算κ统计量。从这五个亚型中，浅表亚型表现出实质性的评分者间一致性(κ=0.64)，其他四种亚型表现出中等的评分者间一致性[结节(κ=0.45)，硬化/形态（κ=0.45），浸润(κ=0.49)和微结节(κ=0.57)]。分为较高或较低风险亚型的两级评级显示出评估者之间的实质性一致性（κ=0.72）。我们的结果表明需要更精确地定义BCC亚型。我们建议使用两级风险分组报告BCC亚型，其次是特定的亚型存在。需要进一步研究较不常见的BCC亚型的评估者间可靠性。
