Sonographic scoring of solid thyroid nodules: effects of nodule size and suspicious cervical lymph node / Escore ultrassonográfico de nódulos sólidos de tireoide: efeitos do tamanho do nódulo e de linfonodo cervical suspeito

Abstract Introduction Ultrasound is the most frequently used imaging method to evaluate thyroid nodules. Sonographic characteristics of thyroid nodules which are concerning for malignancy are important to define the need for fine needle aspiration biopsy or open surgery. Objective To evaluate malignancy risk of solid thyroid nodules through sonographic scoring. The effects of nodule size ≥2 cm and associated pathologic cervical lymph node in scoring were examined in addition to generally excepted suspicious features. Methods Medical data of 123 patients underwent thyroid surgery were reviewed, and 89 patients (58 females, 31 males) were included in the study. The presence and absence of each suspicious sonographic feature of thyroid nodules were scored as 1 and 0, respectively. Total ultrasound score was obtained by adding the positive ultrasound findings. Differently from the literature, nodule size ≥2 cm and associated pathologic cervical node were added in scoring criteria. The diagnostic performance of nodule characteristics for malignancy and the effect of total US score to discriminate malignant and benign disease were calculated. Results A significant relationship was found between malignancy and hypoechogenity, border irregularity, intranodular vascularity, and microcalcification (p < 0.05). Pathologic cervical node was observed predominantly in association with malignant nodules. Positive predictive value of suspicious cervical node for malignancy was 67%, similar to microcalcification. Nodule size ≥2 cm was not distinctive for diagnosis of malignancy. The number of suspicious sonographic features obtained with receiver operating characteristic analysis to discriminate between malignant and benign disease was three. Conclusion Sonographic scoring of thyroid nodules is an effective method for predicting malignancy. The authors suggest including associated pathologic node in the scoring criteria. Further studies with larger cohorts will provide more evidence about its importance in sonographic scoring.

Resumo Introdução A ultrassonografia é o método imagiológico mais frequentemente usado na avaliação de nódulos tireoidianos. As características ultrassonográficas dos nódulos tireoidianos que dizem respeito à malignidade são importantes para a definição da necessidade de uma biópsia por aspiração com agulha fina ou uma cirurgia aberta. Objetivo Avaliar o risco de malignidade de nódulos tireoidianos sólidos por meio de escore ultrassonográfico, verificar os efeitos de nódulos ≥ 2 cm, em associação com linfonodo cervical patológico, além de características suspeitas geralmente omitidas. Método Foram revisados dados médicos de 123 pacientes tratados com cirurgia da tireoide. Foram incluídos no estudo 89 pacientes (58 mulheres, 31 homens). Presença e ausência de cada característica ultrassonográfica suspeita de nódulo tireoidiano receberam pontuações de 1 e 0, respectivamente. O escore ultrassonográfico total foi obtido pela soma dos achados ultrassonográficos positivos. Diferentemente da literatura, nódulos ≥ 2 cm e nodo cervical patológico associado foram acrescentados nos critérios de pontuação. Foram calculados o valor diagnóstico das características dos nódulos para malignidade e o efeito do escore ultrassonográfico total na diferenciação entre doença maligna vs. benigna. Resultados Foi encontrada uma associação significante entre malignidade e hipoecogenicidade, irregularidade das margens, vascularidade intranodular e microcalcificação (p < 0,05). Nodo cervical patológico foi observado predominantemente em associação com nódulos malignos. O valor preditivo positivo de nodo cervical suspeito para malignidade foi de 67%, similar ao achado para microcalcificação. Diâmetro de nódulo ≥ 2 cm não foi fator diferenciador para diagnóstico de malignidade. O número de características ultrassonográficas suspeitas obtido com a análise da curva de características de operação do receptor (receiver operating characteristic, ROC) para discriminação entre doença maligna vs. benigna foi igual a 3. Conclusão O escore ultrassonográfico dos nódulos tireoidianos é método efetivo para predição de malignidade. Sugerimos a inclusão de nódulo patológico associado aos critérios de pontuação. Futuros estudos com coortes maiores proporcionarão mais evidências sobre sua importância no escore ultrassonográfico.

Is the measurement of inferior thyroid artery blood flow velocity by color-flow Doppler ultrasonography useful for differential diagnosis between gestational transient thyrotoxicosis and Graves' disease? A prospective study

OBJECTIVE: To determine the role of peak systolic velocity, end-diastolic velocity and resistance indices of both the right and left inferior thyroid arteries measured by color-flow Doppler ultrasonography for a differential diagnosis between gestational transient thyrotoxicosis and Graves' disease during pregnancy. METHODS: The right and left inferior thyroid artery-peak systolic velocity, end-diastolic velocity and resistance indices of 96 patients with thyrotoxicosis (41 with gestational transient thyrotoxicosis, 31 age-matched pregnant patients with Graves' disease and 24 age- and sex-matched non-pregnant patients with Graves' disease) and 25 ageand sex-matched healthy euthyroid subjects were assessed with color-flow Doppler ultrasonography. RESULTS: The right and left inferior thyroid artery-peak systolic and end-diastolic velocities in patients with gestational transient thyrotoxicosis were found to be significantly lower than those of pregnant patients with Graves' disease and higher than those of healthy euthyroid subjects. However, the right and left inferior thyroid artery peak systolic and end-diastolic velocities in pregnant patients with Graves' disease were significantly lower than those of non-pregnant patients with Graves' disease. The right and left inferior thyroid artery peak systolic and end-diastolic velocities were positively correlated with TSH-receptor antibody levels. We found an overlap between the inferior thyroid artery-blood flow velocities in a considerable number of patients with gestational transient thyrotoxicosis and pregnant patients with Graves' disease. CONCLUSIONS: This study suggests that the measurement of inferior thyroid artery-blood flow velocities with colorflow Doppler ultrasonography does not have sufficient sensitivity and specificity to be recommended as an initial diagnostic test for a differential diagnosis between gestational transient thyrotoxicosis and Graves' disease during pregnancy.