Analysis On The Histopathological Factors In C-TIRADS 5 Signs Of Thyroid Nodules

Purpose To analyze the histopathological basis of C-TIRADS 5 signs of thyroid nodules from the pathological perspective,and to discuss the causes of misdiagnosis by ultrasonography.Methods A total of 600 cases of thyroid nodules with different pathological diagnoses(nodular goiter,subacute thyroiditis,chronic lymphocytic thyroiditis,follicular thyroid adenoma,papillary thyroid carcinoma,follicular thyroid carcinoma,medullary thyroid carcinoma)were collected from the Second Affiliated Hospital of Anhui Medical University during January 2019 to December 2021.Collecting the parenchymal structure – normal/large follicle,microfollicle,papillary structure and interstitial distribution – interstitial fibrosis(none,focal or extensive),inflammatory cells infiltration(none or presence),calcification(none,psammoma body or macrocalcification)of histopathological images by hematoxylin-eosin staining and immunohistochemical staining.Then gathering the 5 positive indicators in C-TIRADS– structure,echo level,boundary,aspect ratio and punctate echogenicfoci in ultrasonic report.The univariate chi-square test and the multivariate unconditional logistic regression analysis were used to conduct these data.Results The malignant rate of nodules was significantly different between solid structure(96.6%)and cystic or cystic solid structure(3.4%)(padj <0.05).Positively histopathological factors of hypoechoic include extensive fibrosis(p<0.001,OR=8.849)> papillary structure(p<0.001,OR=8.685)> microfollicles(p<0.001,OR=4.199)> focal fibrosis(p<0.001,OR=2.728).The factors of ill-defined boundary include extensive fibrosis(p<0.001,OR=8.326)> papillary structure(p<0.001,OR=4.073)> focal fibrosis(p=0.016,OR=1.914)> inflammatory cell infiltration(p=0.042,OR=1.743).The factors of aspect ratio ≥1 include extensive fibrosis(p<0.001,OR=6.765)> papillary structure(p<0.001,OR=4.515)> microfollicles(p=0.049,OR=1.88).The factors of punctate echogenicfoci include papillary structure(p<0.001,OR=18.407)> psammoma body(p=0.031,OR=9.465)> extensive fibrosis(p<0.001,OR=6.594)> macrocalcification(p=0.041,OR=2.602)> focal fibrosis(p=0.011,OR=2.545)> microfollicles(p=0.009,OR=2.452).The malignant rate of C-TIRADS ≥ 4B is 83.3%.Conclusion The C-TIRADS classification system of thyroid nodules were based on pathology as a theoretical basis,and the factors influencing higher ultrasonic classification include dense proliferation of parenchymal cells and interstitial fibrosis,of which extensive fibrosis is the most significant histopathological factor affecting the C-TIRADS 5 signs.Therefore,this result can explain the phenomenon of misdiagnosis of some benign nodules with extensive fibrosis by ultrasonography.Analyzing ultrasonic images from the pathological perspective to provide a histopathological basis and foundation for the C-TIRADS classification system.In this way,the in-depth interpretation of ultrasonic reports can be strengthened to provide new insights and ideas for diagnosis and treatment of thyroid nodules.