Papillary thyroid carcinoma (PTC) is the most common type of thyroid malignancy. Some PTCs with classical papillae can be totally or partially encapsulated, and these tumors are called “encapsulated” (conventional) variant of papillary thyroid carcinoma. We aimed to investigate the clinicopathological features of this variant, comparing with non-encapsulated conventional type PTC. Among 823 thyroidectomy specimens with PTC diagnosed between 2015 and 2018, 121 tumors from 105 patients (12.75%) were reclassified as encapsulated conventional PTC. In 76 patients, tumors were unifocal. Size, cystic changes, background thyroiditis, psammoma bodies, cervical lymph node metastasis at presentation, capsular/vascular invasion, and immunohistochemical BRAF-V600E expression were evaluated. Ninety-two non-encapsulated conventional PTCs served as control group. Encapsulated cases were predominantly women (73.3%), 56.4% were microcarcinomas, 97.5% had cystic changes, 81.4% were BRAF-V600E positive, and 36.8% of unifocal encapsulated tumors had cervical lymph node metastasis. Thyroiditis and psammoma bodies were detected in nearly half of the encapsulated PTCs. Fourteen percent of the unifocal tumors showed total encapsulation, whereas capsular and vascular invasion was detected in 85.5% and 5.8%, respectively. Encapsulated cases did not show any significant difference from the control group, except for prominent cystic changes (p < 0.001). Relationship between lymph node metastasis at presentation and capsular invasion was statistically significant (p = 0.001), and metastasis was more frequent in cases with extensive capsular invasion (no/minimal invasion versus extensive invasion, p < 0.001). Cystic changes are very common, and this feature deserves mentioning as a morphological characteristic of encapsulated conventional PTCs. As in encapsulated “follicular” variant of PTC, capsular invasion status is important in evaluating papillary patterned encapsulated PTC for predicting lymph node metastasis. Total examination of the tumor capsule and inclusion of capsular invasion status in pathology reports are recommended.

甲状腺乳头状癌（PTC）是最常见的甲状腺恶性肿瘤。一些具有经典乳头的PTC可以完全或部分被包裹，这些肿瘤被称为甲状腺乳头状癌的“包裹”（常规）变体。我们的目的是研究这种变体的临床病理学特征，并与非封装的常规型 PTC 进行比较。在 2015 年至 2018 年间诊断为 PTC 的 823 例甲状腺切除标本中，来自 105 名患者（12.75%）的 121 例肿瘤被重新分类为包膜传统 PTC。在 76 名患者中，肿瘤是单灶的。评估大小、囊性变化、背景甲状腺炎、砂粒体、颈部淋巴结转移、包膜/血管侵犯和免疫组织化学 BRAF-V600E 表达。九十二个未封装的常规 PTC 作为对照组。包膜病例以女性为主（73.3%），56.4%为微小癌，97.5%有囊性改变，81.4%为BRAF-V600E阳性，36.8%的单灶包膜肿瘤有颈部淋巴结转移。在近一半的封装 PTC 中检测到甲状腺炎和沙粒体。14% 的单灶性肿瘤显示完全包膜，而分别有 85.5% 和 5.8% 检测到包膜和血管侵犯。除了明显的囊性改变外，包膜病例与对照组没有任何显着差异（在近一半的封装 PTC 中检测到甲状腺炎和沙粒体。14% 的单灶性肿瘤显示完全包膜，而分别有 85.5% 和 5.8% 检测到包膜和血管侵犯。除了明显的囊性改变外，包膜病例与对照组没有任何显着差异（在近一半的封装 PTC 中检测到甲状腺炎和沙粒体。14% 的单灶性肿瘤显示完全包膜，而分别有 85.5% 和 5.8% 检测到包膜和血管侵犯。除了明显的囊性改变外，包膜病例与对照组没有任何显着差异（p  < 0.001)。就诊时淋巴结转移与包膜浸润之间的关系具有统计学意义（p  = 0.001），并且在广泛包膜浸润的情况下转移更频繁（无/最小浸润与广泛浸润，p  < 0.001）。囊性变化非常常见，这一特征值得一提，作为封装的常规 PTC 的形态特征。与 PTC 的包膜“滤泡”变体一样，包膜浸润状态对于评估乳头状包膜 PTC 以预测淋巴结转移很重要。建议对肿瘤包膜进行全面检查，并将包膜侵犯状态纳入病理报告。