浸润性包裹型滤泡亚型甲状腺乳头状癌15例临床病理和分子遗传学特征分析OA

Objective To investigate the clinicopathological characteristics,molecular genetic alterations,and diagnostic key points of invasive encapsulated follicular variant of papillary thyroid carcinoma(IEFVPTC).Methods A retrospective analysis was conducted on 15 IEFVPTC cases confirmed by postoperative pathology.Their clinical manifestations,ultrasonographic features,histological morphology,immunohistochemical profiles,and molecular test⁃ing results were summarized.Results Among the 15 patients,13(86.7%)were female and 2(13.3%)were male,with a median age of 38 years.Preoperative ultrasonography indicated that all nodules(100%)were classified as C-TIRADS 4 or 5.Histologically,all cases exhibited a complete capsule and an entirely follicular growth pattern,with confirmed capsular and/or vascular invasion.The nuclear score of papillary carcinoma showed that 11 cases(73.3%)scored 3 points,and 4 cases(26.7%)scored 2 points.Immunohistochemistry revealed that 13 cases(86.7%)dis⁃played a CD56-negative/CK19,Galectin-3,HBME-1 positive phenotype.Molecular testing identified RAS family mutations in 8 cases(53.3%),including 5 cases of NRAS Q61R mutation and 3 cases of HRAS Q61R mutation,while no BRAF V600E mutation was detected.After a median follow-up of 24 months,no recurrence or metastasis was detected in any patient,expect for one case in which scapular metastasis had already been present at initial diagnosis,and all patients were alive.Conclusion IEFVPTC is a thyroid malignancy with distinct clinicopathological and mo⁃lecular features.The core of its diagnosis lies in identifying capsular/vascular invasion and PTC nuclear features.Its molecular profile is characterized by RAS-like mutations.Combining immunohistochemistry,molecular testing,and emerging technologies like proteomics can aid in differentiating it from low-risk thyroid neoplasms,thereby enabling precise diagnosis and individualized treatment.