Ultrasonographic Features Of The Thyroid Nodules And Its Relationship With Pathological Types And Molecular Markers

【research background】Thyroid nodule is a common disease in clinics. About4%of adults may sufferfrom thyroid nodules. Its incidence has increased with the popular regularexamination and the development of the clinical laboratory. Most of thyroid nodulesare benign，but the incidence of thyroid cancer has increased in recent years. So it isimportant to determine the nature of thyroid nodules before surgical operation，due tothe different treatments and prognosis. Of all the test methods，high resolution ratioultrasonic technology has become the first choice in the diagnosis and differentiationof thyroid nodules，which not only has many advantages as a nondestructive，realtime monitoring， economical and convenient method，but also can show thenumber，size and shape of thyroid nodules clearly. However，pathological types ofthyroid are diverse and ultrasonic manifestation of some nodules is atypical，there aresometimes difficulties in diagnosis on thyroid mass，a certain portion of cases havebeen misdiagnosed. Some researches have showed that the technology of fine-needleaspiration biopsy with the guidance of B-type ultrasound can improve the accuracy ofdiagnosis before operation，otherwise we may further detect some tumor-relatedmolecular markers，it can be useful to make diagnosis definite and prognosisassessment，also helpful to make the diagnosis and treatment plan individually. Theprocess of carcinogenesis in thyroid nodules need multi-genes and multi-steps，inwhich many genetic mutations take place and related cytokines change includinghTERT，Ki67，VEGF，Ret，P53and other tumor-related genes.Our early experimentshave indicated that these tumor-related genes not only have close relationship tobiological characteristics of thyroid cancer but also to the ultrasonographic features.So we have concluded initially that the ultrasonographic features of thyroid cancer have been related to the tumor biological characteristics.Therefore，we continue to research the relationship among ultrasonographicfeatures，pathological findings and molecular markers by adding benign cases toresearch for comparison. We think it can provide further help for diagnosis andprognosis assessment of thyroid nodules.【Objective】We detected the features of the thyroid nodules and cervical lympho node byultrasound and color Doppler flowing imaging. These data were analyzed to researchits relationship with the pathological types of thyroid nodules and the expression ofthyroid tumor-related genes.The aim of this study was to estimate the value ofdiagnosis and prognosis of color Doppler ultrasound in thyroid nodules cases.【Methods】1. One hundred and twenty samples were divided into two groups including thirtybenign samples and ninety malignant ones. The data of all samples which underwentcolor Doppler ultrasonographic examination before surgical operation were evaluatedand compared with final histopathological diagnoses. So the accuracy of ultrasoundexamination was calculated.2. One hundred and thirty samples were divided into three groups（ten normalthyroid sample were added to research），including thirty benign samples，ten normalsamples and ninety malignant ones. All samples in three groups were determined byconsecutive pathological section and immunohistochemical method，we can getexpression positive rate of tumor-related genes. And then the relationship betweenultrasonic characteristics and tumor gene expression was analyzed.【Results】1、The ultrasound findings of benign thyroid nodules were regular shape，defined edge，cystic echo or solid-and-cystic echo，macro calcification，A/T＜1andrare blood-flow without lymph nodes metastasis，while characteristics of malignantcases were irregular appearance， ill-defined edge， hypoechogenicity， micro calcification，A/T≥1with increased blood flow（grade III）and lymph nodemetastasis，which were statistically different between benign and malignant group.The sensitivity of above five ultrasound findings were56.7%、85.6%、73.3%、38.9%and87.8%in diagnosis of thyroid cancer，while they were96.6%，100%，100%，93.3%and100%in diagnosis of benign thyroid nodules.2、Expression positive rate of hTERT、 Ki67、VEGF、Ret and P53gene was82.2%，77.8%，85.6%，90%g and85.6%in malignant group，while neither hadpositive expression in other two group. It was statistically different between benignand malignant cases but not statistically different between benign group and normaltissue.3、 In malignant group， the positive rate of hTERT in groups withhypoechogenicity，micro calcification，increased blood flow，nodules’s A/Tratio(≥1) and lymph node metastasis were more than it in the groups without thesefeatures，but it had nothing to do with irregular margin.The positive rate of Ki67genein groups with irregular margin，hypoechogenicity，micro calcification，increasedblood flow and nodules’s A/T ratio(≥1) were more than it in the group without thesefeatures，but it had nothing to do with lymph-node metastasis. VEGF gene’s positiveexpression in the group with irregular margin，hypoechogenicity，micro calcification，increased blood flow，nodules’s A/T ratio(≥1) and lymph node metastasis weremore than it in the group without these features. So the same results appeared in thepositive rate of Ret gene and P53gene.【Conclusions】1、Color Doppler ultrasound has a high sensitivity in detecting thyroid nodules.It is a valuable tool in early diagnosis of thyroid cancer and differential diagnosis ofthyroid nodules.2、Edge，inside echo，micro calcification，A/T ratio of nodule and blood flowwere five important features in differential diagnosis of thyroid nodules.3、The pathological characteristic and expression of tumor relative genes arerelated to ultrasonographic features of thyroid cancer，which can provide pathological basis for ultrasonographic features of thyroid cancer，and also be useful to assessingprognosis.