Even basic ultrasonographic characteristics (shape, echogenicity and echogenic hilum, calcifications, and intranodal cystic necrosis) help in the differentiation between metastatic and nonmetastatic lymph nodes in patients with papillary thyroid carcinoma.

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.

Preparation with recombinant human thyroid-stimulating hormone (rhTSH) for thyroid remnant ablation results in lower extrathyroidal radiation than does hypothyroidism. The objective of this prospective study was to compare the damage caused by 131 I (3.7 GBq) when these 2 preparations are used. Methods: Ninety-four consecutive patients who underwent total thyroidectomy and remnant ablation with 3.7 GBq of 131 I were studied. Thirty patients (group A) received rhTSH, and 64 (group B) were prepared by levothyroxine withdrawal. Damage to salivary glands, ovaries, and testes; hematologic damage; and oxidative injury were evaluated by measurement of serum amylase, folliclestimulating hormone (FSH), complete blood count, and plasma 8-epi-PGF 2a before and after radioiodine. The 2 groups were similar in sex, age, and the results of baseline assessment. Results: The rate of successful ablation (stimulated thyroglobulin level , 1 ng/mL and negative findings on neck ultrasonography) was 90% in group A and 80% in group B. Considering only patients with a preablation thyroglobulin level greater than 1 ng/mL, these rates were 80% and 70.6%, respectively. Only 1 patient (3.3%) reported transient headaches with rhTSH. Elevated FSH levels after therapy were observed in 4 of 9 (44%) men in group A versus 16 of 18 (89%) in group B (P , 0.03), with a mean increase of 105% versus 236% (P , 0.001), respectively. In women, elevated FSH was observed in 1 of 13 (7.7%) patients in group A versus 6 of 30 (20%) in group B (P 5 0.4), with a mean increase of 65% versus 125% (P , 0.001). Thrombocytopenia or neutropenia occurred in 2 of 28 (7%) patients in group A versus 12 of 56 (21.4%) in group B (P 5 0.1), with a mean decrease of 20% versus 45% and 25% versus 52% (P , 0.01) for neutrophils and platelets, respectively. Hyperamylasemia and symptoms of acute sialoadenitis occurred in 11 of 30 (36.6%) versus 48 of 60 (80%) (P , 0.001) and in 9 of 30 (30%) versus 35 of 60 (58.3%) (P 5 0.01), respectively. 8-Epi-PGF 2a was found to be elevated after 131 I in 14 of 25 (56%) patients in group A versus 45 of 45 (100%) in group B (P , 0.001), with a mean increase of 60% versus 125% (P , 0.001). Conclusion: The lower radiotoxicity with rhTSH, suggested in dosimetry studies, was confirmed in the present prospective investigation, and this advantage occurred without compromising the efficacy of treatment.

Our aim was to assess testicular function in patients treated with high-dose radioiodine. Luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone levels were determined in 52 men with thyroid carcinoma before and 6, 12, and 18 months after radioiodine therapy (3.7-5.5 GBq 131 I; mean, 4.25 GBq 131 I) (group 1) and were also determined before and 18 months after the last radioiodine therapy in 22 patients who received high cumulative activities (13-27.7 GBq; mean, 20.3 GBq 131 I) (group 2). FSH levels were increased 6 months after therapy in all patients of group 1, while a decline was observed after 12 months, with 37 of 52 (71%) subjects presenting normal values. FSH values returned to normal after 18 months in all patients. In group 2, 12 of 22 (54.5%) patients presented elevated FSH and 8 (66%) of these individuals had oligospermia. Six months after radioiodine, increased LH levels were observed in only 5 of 52 (9.6%) patients of group 1, which returned to normal after 12 months, and in 5 of 22 (22%) of group 2. All patients showed normal testosterone levels. We conclude that 131 I therapy may cause impairment of testicular function. A generally transient increase in FSH is highly common but is usually reversed within 18 months. Oligospermia was common (one third) after high cumulative 131 I activities. Becausee we did not perform a spermiogram before therapy, we cannot state that high cumulative 131 I activities cause permanent infertility. We recommend the routine use of sperm banks in the cases of men who still wish to have children and who will undergo therapy with 131 I activities of 14 GBq or more or in the case of patients with pelvic metastases. 667

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% 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 ≥ 4 cm does not justify systematic resection of these nodules in asymptomatic patients with benign cytology. Arq Bras Endocrinol Metab. 2009;53(9):1143-5Keywords Thyroid nodule; cytology; benign resumo Objetivo: Reportar os resultados da citologia e da histologia em uma série de nódulos tireoidianos ≥ 4 cm sistematicamente ressecados. Métodos: Foram submetidos à cirurgia 151 pacientes com nódulo tireoidiano ≥ 4 cm, a despeito do resultado da citologia. Apenas a histologia referente a este nódulo foi considerada nos resultados. Resultados: Malignidade foi confirmada histologicamente em 22,5% dos pacientes. Excluindo os casos com material insuficiente, a citologia foi benigna somente em 3/31 carcinomas (sensibilidade 90,3%). A frequência de malignidade foi de 35% nos nódulos com citologia indeterminada (neoplasia folicular), predominando o carcinoma papilífero (77%). O valor preditivo negativo da citologia benigna foi 96,4%. Conclusões: A taxa de falso-negativo da citologia em nódulos tireoidianos ≥ 4 cm não justifica a ressecção sistemática destes em pacientes assintomáticos com citologia benigna. Arq Bras Endocrinol Metab. 2009;53(9):1143-5 Descritores Nódulo da glândula tireoide; citologia; benigna

Objective. To determine the sensitivity of thyroglobulin (Tg), iodine scanning, and sonography in the diagnosis of cervical recurrence of thyroid cancer. Methods. This prospective study assessed 81 patients with cervical metastases or extrathyroid invasion at first appearance who underwent clinical examination, scanning, measurement of Tg after thyroxine withdrawal, and sonography about 8 months after thyroidectomy followed by radioiodine treatment. Only patients without distant metastases and without anti‐Tg antibodies were included. Results. Fifty patients showed persistence of the disease in the cervical region, with only 16% of them having had a suspicion on clinical examination, 33 with Tg levels of 2 ng/mL or greater (66% sensitivity), and 29 with positive scan findings (58% sensitivity). A combination of the 2 methods detected disease in 40 (80%) of 50 patients but failed to show 20% of cases that were identified by sonography and confirmed by fine‐needle aspiration. Sonography had sensitivity of 96%. Specificity values for Tg, iodine scanning, and sonography were 80.6%, 90.3%, and 87%, respectively. Conclusions. Classic follow‐up methods may not detect cervical disease in some patients with differentiated thyroid carcinoma, and sonography is necessary even in patients apparently free of the disease.

Posttherapy scanning provides important information, even in patients whose pretherapy WBS is positive for metastases, with this approach being useful both during the first ablation and subsequent treatment.

Undetectable Tg on T4 combined with negative neck US presented a high NPV in low-risk patients and Tg stimulation might be avoided in these patients.