The assessment of capsular invasion is an essential but challenging step in the diagnosis of encapsulated follicular thyroid neoplasms. Therefore, interobserver agreement in the assessment of capsular invasion in these tumors was investigated among 11 thyroid pathologists by using virtual slides of 20 cases in which the original diagnosis considered the differential diagnosis of definite capsular invasion versus questionable capsular invasion. The assessment of capsular invasion was divided into three categories: (1) non-invasive, (2) questionable invasive, and (3) clear-cut invasive. The interobserver agreements for clear-cut invasive and non-invasive categories were fair (Kappa value = 0.578 and 0.404, respectively), whereas agreement for the questionable invasion was poor (Kappa value = 0.186). Disagreements in the assessment of invasion resulted in variable final pathological diagnoses. For example, the agreement for a diagnosis of malignancy was only fair (Kappa value = 0.545). Moreover, pathologists did not have a uniform approach for rendering a final diagnosis in cases with questionable capsular invasion, though nine of 11 pathologists did use the follicular tumor of uncertain malignant potential diagnosis as proposed by the World Health Organization classification of endocrine organs published in 2017. In conclusion, this study revealed considerable interobserver variation in the evaluation of capsular invasion, especially in follicular neoplasms with questionable invasion.

中文翻译：

---

滤泡性甲状腺肿瘤包膜浸润的组织病理学评估-观察者变异研究。

包膜浸润的评估是诊断包囊滤泡性甲状腺肿瘤中必不可少但具有挑战性的步骤。因此，通过使用20例虚拟载玻片，在11位甲状腺病理学家中调查了观察者之间的共识，以评估这些肿瘤的包膜浸润，其中原始诊断考虑了明确的包膜浸润与可疑的包膜浸润的鉴别诊断。包膜浸润的评估分为三类：（1）非浸润性；（2）可疑浸润性；（3）明确浸润性。明确的侵入性和非侵入性类别的观察员之间协议是公平的（Kappa值分别为0.578和0.404），而对于可疑入侵的协议则差强人意（Kappa值= 0.186）。评估入侵的分歧导致最终病理诊断可变。例如，诊断恶性肿瘤的协议是公正的（Kappa值= 0.545）。此外，病理学家并没有统一的方法对可疑的荚膜浸润病例做出最终诊断，尽管11位病理学家中有9位确实使用了根据世界卫生组织于2017年发布的内分泌器官分类法对恶性潜力进行不确定诊断的滤泡性肿瘤总之，这项研究揭示了在观察包膜浸润，尤其是在滤泡浸润有可疑浸润的肿瘤中，观察者之间存在很大差异。