Contribution of scintigraphy and ultrasonography to the prediction of malignancy in thyroid nodules with indeterminate cytology.

OBJECTIVE: To evaluate the contribution of (131)I scintigraphy and ultrasonography to the prediction of malignancy in thyroid nodules with indeterminate cytology in euthyroid patients. SUBJECTS AND METHODS: The sample consisted of 102 patients with thyroid nodules, submitted to FNAC and presenting an indeterminate cytological diagnosis (follicular neoplasm). RESULTS: Malignancy was observed in 19/25 (76%) nodules with suspicious ultrasonographic characteristics versus 5/77 (6.5%) without suspicious findings. When (131)I scintigraphy showed a cold or hot nodule, the chance of malignancy was 38.5% and 2.5%, respectively. This exam was inconclusive in 10% of the patients. CONCLUSIONS: Surgery is indicated when a thyroid nodule with indeterminate cytology exhibits suspicious ultrasonographic characteristics. Otherwise, (131)I scintigraphy can exclude thyroidectomy when reveals uptake in the nodule, which is observed in half the cases.

Contribution of scintigraphy and ultrasonography to the prediction of malignancy in thyroid nodules with indeterminate cytology / Contribuição da cintilografia e ultrassonografia para a predição de malignidade em nódulos tireoidianos com citologia indeterminada

OBJECTIVE: To evaluate the contribution of 131I scintigraphy and ultrasonography to the prediction of malignancy in thyroid nodules with indeterminate cytology in euthyroid patients. SUBJECTS AND METHODS: The sample consisted of 102 patients with thyroid nodules, submitted to FNAC and presenting an indeterminate cytological diagnosis (follicular neoplasm). RESULTS: Malignancy was observed in 19/25 (76 percent) nodules with suspicious ultrasonographic characteristics versus 5/77 (6.5 percent) without suspicious findings. When 131I scintigraphy showed a cold or hot nodule, the chance of malignancy was 38.5 percent and 2.5 percent, respectively. This exam was inconclusive in 10 percent of the patients. CONCLUSIONS: Surgery is indicated when a thyroid nodule with indeterminate cytology exhibits suspicious ultrasonographic characteristics. Otherwise, 131I scintigraphy can exclude thyroidectomy when reveals uptake in the nodule, which is observed in half the cases.

OBJETIVO: Avaliar a contribuição da cintilografia com 131I e da ultrassonografia na predição de malignidade em nódulos tireoidianos com citologia indeterminada em pacientes eutireoidianos. SUJEITOS E MÉTODOS: A amostra foi composta por 102 pacientes com nódulos tireoidianos submetidos à punção aspirativa com agulha fina (PAAF), apresentando citologia indeterminada (neoplasia folicular). RESULTADOS: Malignidade foi encontrada em 19/25 (76 por cento) nódulos suspeitos na ultrassonografia versus 5/77 (6,5 por cento) naqueles sem características suspeitas. Quando a cintilografia com 131I mostrou nódulo hipo- ou hipercaptante, a chance de malignidade foi 38,5 por cento e 2,5 por cento, respectivamente, e em 10 por cento dos pacientes esse exame foi inconclusivo. CONCLUSÕES: Cirurgia está indicada quando um nódulo tireoidiano com citologia indeterminada exibe características ultrassonográficas suspeitas. Quando não as exibe, a cintilografia com 131I pode dispensar a tireoidectomia se revelar captação correspondente ao nódulo, o que ocorre em metade dos casos.

Low false-negative rate of cytology in thyroid nodules ¡Ý 4 cm / Baixa taxa de falso-negativo da citologia em n¨®dulos tireoidianos ¡Ý 4 cm

OBJECTIVE: To report the results of cytology and histology obtained for a series of systematically resected thyroid nodules > 4 cm. METHODS: A group of 151 patients with thyroid nodules > 4 cm was submitted to surgery despite the cytology result. RESULTS: Malignancy was confirmed histologically in 22.5 percent of the patients. Excluding cases of insufficient material, cytology was benign in only 3/31 carcinomas (90.3 percent sensitivity). The frequency of malignancy was 35 percent among nodules with indeterminate cytology (follicular neoplasm), and there was a predominance (77 percent) of papillary carcinoma. The negative predictive value of benign cytology was 96.4 percent. CONCLUSIONS: The false-negative rate of cytology in thyroid nodules > 4 cm does not justify systematic resection of these nodules in asymptomatic patients with benign cytology.

OBJETIVO: Reportar os resultados da citologia e da histologia em uma s¨¦rie de n¨®dulos tireoidianos > 4 cm sistematicamente ressecados. MÉTODOS: Foram submetidos ¨¤ cirurgia 151 pacientes com n¨®dulo tireoidiano > 4 cm, a despeito do resultado da citologia. Apenas a histologia referente a este n¨®dulo foi considerada nos resultados. RESULTADOS: Malignidade foi confirmada histologicamente em 22,5 por cento dos pacientes. Excluindo os casos com material insuficiente, a citologia foi benigna somente em 3/31 carcinomas (sensibilidade 90,3 por cento). A frequ¨ºncia de malignidade foi de 35 por cento nos n¨®dulos com citologia indeterminada (neoplasia folicular), predominando o carcinoma papil¨ªfero (77 por cento). O valor preditivo negativo da citologia benigna foi 96,4 por cento. CONCLUSÕES: A taxa de falso-negativo da citologia em n¨®dulos tireoidianos > 4 cm não justifica a ressecção sistem¨¢tica destes em pacientes assintom¨¢ticos com citologia benigna.

Low false-negative rate of cytology in thyroid nodules >or= 4 cm.

OBJECTIVE: To report the results of cytology and histology obtained for a series of systematically resected thyroid nodules >or= 4 cm. METHODS: A group of 151 patients with thyroid nodules >or= 4 cm was submitted to surgery despite the cytology result. RESULTS: Malignancy was confirmed histologically in 22.5% of the patients. Excluding cases of insufficient material, cytology was benign in only 3/31 carcinomas (90.3% sensitivity). The frequency of malignancy was 35% among nodules with indeterminate cytology (follicular neoplasm), and there was a predominance (77%) of papillary carcinoma. The negative predictive value of benign cytology was 96.4%. CONCLUSIONS: The false-negative rate of cytology in thyroid nodules >or= 4 cm does not justify systematic resection of these nodules in asymptomatic patients with benign cytology.

Natural history of mild subclinical hypothyroidism: prognostic value of ultrasound.

BACKGROUND: Clinical repercussions, progression to overt hypothyroidism, and treatment benefits have been well established in patients with subclinical hypothyroidism (SCH) and TSH >10 mIU/L. In contrast, these aspects of the disease are poorly understood in patients with even milder SCH as defined by TSH < or = 10 mIU/L and normal thyroid hormone levels. Therefore, we sought to evaluate the natural history of this milder form of SCH (TSH < or =10 mIU/L with normal thyroid hormone levels) in adult women patients. PATIENTS: One hundred seventeen patients with TSH levels ranging from 5 to 10 mIU/L and normal free T4, without a previously known history of thyroid disease, were followed for a period of 3 years and had two consecutive assessments. RESULTS: Sixty patients tested positive for antithyroperoxidase antibodies (TPOAb) and 36 were TPOAb negative but had diffuse hypoechogenicity on thyroid ultrasound (US). Twenty-one patients were TPOAb negative and had normal US. During follow-up, 20.5% of the patients had spontaneous normalization of their TSH, 27.3% required replacement therapy with levothyroxine (L-T4) because of progression to overt hypothyroidism or persistence of serum TSH >10 mIU/L, and 52.1% continued to meet the criteria for mild SCH (persistence of TSH < or =10 mIU/L). If the patients were classified into two groups, one with positive TPOAb and/or US alteration and the other with testing negative for TPOAb and not having US alteration, the first group had a greater progression toward overt hypothyroidism (31.2% vs. 9.5%, respectively) and a lower rate of normalization of TSH (15.6% vs. 43% respectively). These rates were similar in TPOAb-positive patients and patients with negative TPOAb but with positive US. CONCLUSIONS: Most patients with SCH and TSH < or = 10 mIU/L do not progress to overt hypothyroidism. The presence of chronic thyroiditis as demonstrated by US increases the evolution of SH to overt hypothyroidism or more severe SCH and thus the need for L-T4 treatment. US findings are important in determining the prognosis of mild SCH.