Management of infracentimetric thyroid nodules with respect to ultrasonographic features.

An assumed indolent course of thyroid microcarcinomas and concerns about the cost-effectiveness of treatment raise management issues. As various studies have reported controversial results, management remains unclear. The purpose of this study was to examine the use of ultrasonography (US) in detecting malignancies in a series of 589 infracentimetric nodules. Results of fine-needle aspiration biopsies (FNAB) revealed 503 nodules with adequate cytology. Of these, 473 (94%) were benign, 13 (2.6%) were suspicious for malignancy, 13 (2.6%) were malignant, and 4 (0.8%) were follicular neoplasms. Hypoechogenicity and accompanying lymphadenopathy were the independently significant features in detecting malignancies. Certain combinations of US features increase the significance and predictive value for malignant cytology particularly in the presence of lymphadenopathy. When the postoperative histological results of ten patients with a final diagnosis of papillary carcinoma were evaluated for extent of disease, seven (70%) had one or more of the findings of multifocality, metastatic lymph nodes, or extracapsular involvement, thus proving their clinical significance. Our results indicate that thyroid microcarcinomas should be taken seriously if there are possible signs of malignancy on US. With respect to the high benign nature of the micronodules (94%), the number of interventional procedures should be lowered by making assessments based on a combination of US features including lymphadenopathy.