Growth rates of malignant and benign thyroid nodules in an ultrasound follow-up study: a retrospective cohort study.

BACKGROUND: Thyroid nodules are frequently detected by cervical ultrasound examinations. In follow-up studies, malignant as well as benign nodules may exhibit an increase in size. The objective of our investigation was to test whether histologically determined malignant and benign thyroid nodules show differences in growth rates above a defined significance level. METHODS: A retrospective ultrasound cohort follow-up study from 4 to 132 months included 26 patients with differentiated carcinomas and 26 patients with adenomas of the thyroid gland. Significance levels were determined by intra- and interobserver variations of volumetric measurements in 25 individuals. RESULTS: Intra- and interobserver volumetric measurements were highly correlated (r = 0.99 and r = 0.98, respectively), with variations of 28 and 40%, respectively. The growth rates of malignant and benign nodules did not show differences with respect to two sonographic measurements (d = - 0.04, 95%CI(P): 0.41-0.85, P = 0.83). Using shorter increments and multiple measurements, growth rates of malignant nodules revealed significantly higher values (d = 0.16, 95%CI(P): 0.02-0.04, P = 0.039). CONCLUSIONS: The growth rates of benign and malignant thyroid nodules do not appear to differ using two sonographic volumetric measurements. However, due to temporal changes in cellular proliferation and arrest, malignant nodules may exhibit higher growth rates with multiple assessments and shorter increments.

Fine-needle aspiration biopsies of thyroid nodules.

OBJECTIVE: The purpose of the study was the characterization of adverse events (AEs) after fine-needle aspiration biopsies (FNABs) of thyroid nodules, as well as possible predisposing factors. METHODS: A total of 205 patients, each of whom had undergone an FNAB of a thyroid nodule, were included in the study (15 of whom were taking anticoagulant medication). The thyroid nodules were classified according to the ultrasound criteria of the American Thyroid Association (ATA). The FNABs were carried out by four trained nuclear medicine specialists from two institutions. To detect AEs, all patients were asked to fill out a standardized self-assessment questionnaire. RESULTS: Out of 205 patients, 189 (92 %) reported no AEs. Fourteen patients (6.8 %) had mild or moderate AEs, such as short-term pain at the puncture site. In two patients (1 %), the AEs were classified as significant, and required medical followup, which revealed an intrathyroid hematoma in one patient and dysphonia in the other. All AEs were reversible. None of the patients taking anticoagulants experienced any AEs. The parameters of age, sex, nodule volume, ATA nodule type, needle size, and physician performing the biopsy were not predisposing factors for side effects (p = 0.54, p = 0.73, p = 0.75, p = 0.94, p = 0.35, and p = 0.24, respectively). CONCLUSIONS: The vast majority of patients tolerated the FNAB very well. AEs were seldom observed. A small number of patients experienced AEs that required no intervention or could be self-managed by the patient. Considering the almost negligible risk of the procedure, FNAB should be increasingly used for the classification of thyroid nodules. ZIEL:: Das Ziel der Studie war die Erfassung unerwünschter Wirkungen (UWs) nach Feinnadelaspirationsbiopsien (FNABs) von Schilddrüsenknoten und mögliche hierfür prädisponierende Faktoren. METHODIK: 205 Patienten, bei denen eine FNAB wegen eines Schilddrüsenknotens erfolgte, wurden in die Studie eingeschlossen (hiervon 15 Patienten mit gerinnungshemmender Medikation). Die Schilddrüsenknoten, wurden gemäß Ultraschallkriterien der American Thyroid Association (ATA) klassifiziert. Die FNABs erfolgten durch vier trainierte Nuklearmediziner aus zwei Institutionen. Für die Erfassung von UWs erhielten alle Patienten einen standardisierten Selbstbeurteilungsfragebogen. ERGEBNISSE: Von 205 Patienten gaben 189 (92 %) keine UWs an. 14 Patienten (6,8 %) hatten geringe oder moderate UWs - wie Schmerzen an der Punktionsstelle von kurzer Dauer. Bei zwei Patienten (1 %) wurden die UWs als relevant klassifiziert und erforderten eine ärztliche Nachuntersuchung. Dabei wurde ein intrathyreoidales Hämatom bzw. eine Dysphonie diagnostiziert. Alle UWs waren reversibel. Bei keinem Patienten, der Antikoagulanzien erhielt, fand sich eine UW. Die Parameter Alter, Geschlecht, Knotenvolumen, ATA Knotentyp, Punktionsnadelstärke sowie durchführender Arzt waren für UWs keine prädisponierenden Faktoren (jeweils mit p = 0,54, p = 0,73, p = 0,75, p = 0,94, p = 0,35, p = 0,24, resp.). SCHLUSSFOLGERUNG: Die große Mehrheit von Patienten toleriert die FNAB sehr gut. UWs wurden selten beobachtet. UWs, die bei einer kleinen Zahl von Patienten auftreten, bedürfen entweder keiner Intervention oder können durch die Patienten selbst gemanagt werden. Aufgrund eines fast vernachlässigbaren Risikos sollte die FNAB zur Dignitätsabklärung von Schilddrüsenknoten verstärkt eingesetzt werden.

Ultrasound characteristics of thyroid nodules diagnosed as follicular neoplasms by fine-needle aspiration cytology. A prospective study with histological correlation.

UNLABELLED: Cytopathological evaluation has been proven useful in the diagnostic work-up of "cold" nodules. The cytological diagnosis of follicular neoplasm usually requires histology to exclude malignancy. The objective of this prospective study was to test the hypothesis that ultrasound examinations show distinct characteristics in a subgroup of nodules which may attest the benign nature of a follicular neoplasm. PATIENTS, METHODS: 56 patients (45 women, 11 men) were included in the study. All patients had a "cold" nodule which was diagnosed as follicular neoplasm. Consecutive histology revealed follicular adenomas (FTAs) (n = 44), follicular carcinomas (FTCs) (n = 7) and papillary carcinomas (PTCs) (n = 5), including follicular variant papillary carcinomas (fv PTCs) (n = 4). Ultrasound examinations were performed preoperatively. The ultrasound examinations were evaluated with respect to seven characteristics. RESULTS: In 21 % of patients a follicular neoplasm was associated with a malignant and in 79 % of patients with a benign tumor as compared with histology. The ultrasound characteristics size ≤ 2 ml, round shape and homogeneous structure revealed significant differences for FTAs, FTCs and PTCs with p < 0.001, p = 0.003 and p = 0.027, resp. With respect to the benign nature of a follicular neoplasm maximum values for sensitivity and specificity were 0.75 and 0.83. Multivariate discriminant analysis revealed that ultrasound criteria were suitable to discriminate between benign vs. malignant nodules and among FTAs, FTCs and PTCs with correlation coefficients of r = 0.53 and r = 0.74, resp. CONCLUSIONS: in selected patients with higher operative risks and cytological diagnosis of follicular neoplasm ultrasound parameters may be helpful to assume a benign nature of the neoplasm and thus avoid the necessity of a histological work-up.