engleski

Ultrasound and Fine-Needle Aspiration Biopsy in Diagnosis of Thyroid nodules

Population studies suggest that 4-8 % of asymptomatic adults have thyroid nodules. As increasing numbers of patients undergo ultrasound examination for medical evaluations, more and more thyroid nodules are being detected, in 20-40% of examined patients. Nodular thyroid disease is a heterogeneous disorder with regard to clinical, functional or histological aspects: nodules can be single or multiple, hyper or hypo functional, nodular goitre, benign or malignant tumours. It can be associated with autoimmune thyroid diseases. Malignant nodules account for approximately 3-5 % of all nodules. Ultrasonically guided fine-needle biopsy is method of choice for determining the risk of malignancy. Ultrasound guidance enables biopsies of the lesions 2-3 mm in diameter. Understanding of histological presentation of nodules helps in understanding of echographic presentation, making the echographic critera of malignancy.Colour Doppler is additional tool for understanding vascularity of nodules. In our study of about 1000 carcinomas, in 50% of analysed cases thyroid carcinoma is recognized by ultrasound due its typical presentation like a hypoehogenic nodule of irregular shape or with calcifications. Specificity for these findings is high 97 %, but sensitivity is 50 %, because 33 % of thyroid carcinomas are presented as hypoehogenic nodules of regular contour, as micro-follicular adenomas and micro-follicular nodular goitres. Isoechogenic nodule, with echostructure similar as normal thyroid, surrounded with “ halo” , is of low probability of malignancy although 14% of thyroid cancers show such echopattern. 2% of carcinomas are presented in a form of a cyst with solid tissue inside. Ultrasonically guided cytology is a highly specific method, 97%, and quite sensitive, about 90%, in the diagnosis of papillary and medullary carcinoma, but the most difficult is diagnosis of follicular and Hurthle cell carcinoma. Therefore, the cytological finding can be given as “ follicular tumour” only, and cannot strictly specify whether we are dealing with adenoma or carcinoma. If we include cytological finding follicular tumour as positive finding for thyroid carcinoma sensitivity rises to 95%. Experienced examiner can recognise metastatic lymph node due to its round shape, or more ehogenic, irregular or cystic appearance or abnormal peripheral vascularity but metastatic lymph node can look like benign hyper-plastic lymph node as well. Lymph node metasteses usually are situated on the same side as primary tumour, but in 15% of cases with lymph node metastases bilateral metastases were found. If lymph node metastases are diagnosed lymph node dissection is performed at the same time with total thyroidectomy. Conclusion: Thyroid nodules are common and heterogeneous disorder, therefore the suggestion for optimal management of patients with thyroid nodules is good education and experience in all fields of diagnostics and therapy of thyroid diseases.

Thyroid nodules; Ultrasound; Fine-Needle Aspiration Biopsy

nije evidentirano