Capsular Invasion Matters Also in “Papillary Patterned” Tumors: A Study on 121 Cases of Encapsulated Conventional Variant of Papillary Thyroid Carcinoma

AbstractPapillary 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 p atients (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 eva luated. 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. Thyr oiditis 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 nod...
Source: Endocrine Pathology - Category: Pathology Source Type: research