World J Surg DOI 10.1007/s00268-013-2355-4
Thyroid Nodules with Benign Cytology: Is Size ‡4 cm an Indication for Surgery? Pedro Weslley Rosa´rio
Ó Socie´te´ Internationale de Chirurgie 2013
Recently, Wharry et al. [1] reported the malignancy rate for 382 thyroid nodules. First, except for purely cystic or autonomous nodules, fine-needle aspiration (FNA) is recommended for nodules C4 cm, irrespective of clinical history and ultrasonographic features [2]. Second, in these cases (non-autonomous nodules C4 cm), consensus exists regarding the indication for thyroidectomy if cytology is suspicious of malignancy, malignant, indeterminate, or non-diagnostic [2]. Therefore, considering these aspects (systematic indication for FNA and surgery when the cytology result is not benign), the results of that series [1] are in accordance with current recommendations [2]. Controversy exists regarding the proposal that patients with nodules C4 cm should be submitted to thyroidectomy even when cytology is benign [1]. This recommendation was based on a false-negative rate of 10 % for FNA [1]. One limitation of the study of Wharry et al. [1] is that the rate of malignancy was extracted from a subgroup of patients referred for thyroidectomy. It is reasonable to assume that this subgroup had characteristics of a higher risk for malignancy than the subgroup in which the clinicians decided to use observation. This pre-selection may have overestimated the rate of false-negative FNA results. It would therefore be necessary to evaluate all cases in order to define the true frequency of malignancy in nodules C4 cm with benign cytology. Analyzing the series of Table 5 in the article of Wharry et al. [1], the malignancy rates were also extracted from a subgroup of patients referred for surgery, except for two studies [3, 4]. In the
P. W. Rosa´rio (&) Endocrinology Service, Santa Casa de Belo Horizonte, Rua Domingos Vieira, 590, Santa Efigeˆnia, Belo Horizonte, Minas Gerais CEP 30150-240, Brazil e-mail: [email protected]
first study, Porterfield et al. [3] reported the evolution of 742 patients with nodules C3 cm with benign cytology: (i) of 145 nodules submitted to surgery, only one was malignant, and (ii) none of the more than 500 patients not submitted to thyroidectomy developed apparent malignancy after 3 years of follow-up. The second study was conducted at our service [4], where all patients with nodular disease are first seen by endocrinologists (patients have no direct access to surgeons) and those with nodules C4 cm were systematically referred for surgery after FNA. We showed that only 3 of 84 nodules C4 cm with benign cytology were malignant [4]. The results of these studies, the only ones reporting the evolution of all patients with large nodules with benign cytology and not only that of a subgroup submitted to surgery [3, 4], do not support the proposal that every nodule C4 cm should be removed [1]. Since Wharry et al. [1] did not evaluate nodules \4 cm, it is not possible to conclude that the false-negative rate of 10 % found for nodules C4 cm is due to the size of the nodules or is an inherent limitation of FNA. Analyzing the series of Table 5 in the article of Wharry et al. [1], we found that only six series compared the false-negative rate of FNA between larger versus smaller nodules and no difference was observed in four of them. Moreover, these four series together evaluated 464 large nodules with benign cytology, whereas the two series showing a higher false-negative rate of FNA for larger nodules together evaluated only 51 nodules. If it is not possible to ensure that the size of the nodule contributes to the false-negative rate of FNA, it does not seem to be reasonable to adopt this criterion for the indication of surgery in asymptomatic patients with benign cytology. Acknowledgments interest.
The author declares no potential conflicts of
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World J Surg
References 1. Wharry LI, McCoy KL, Stang MT et al (2013) Thyroid nodules (C4 cm): can ultrasound and cytology reliably exclude cancer? World J Surg. doi:10.1007/s00268-013-2261-9 2. Cooper DS, Doherty GM, Haugen BR et al (2009) Revised American Thyroid Association management guidelines for patients with thyroid nodules and differentiated thyroid cancer. Thyroid 19:1167–1214
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3. Porterfield JR Jr, Grant CS, Dean DS et al (2008) Reliability of benign fine needle aspiration cytology of large thyroid nodules. Surgery 144:963–968 discussion 968–969 4. Rosario PW, Salles DS, Bessa B et al (2009) Low false-negative rate of cytology in thyroid nodules C4 cm. Arq Bras Endocrinol Metabol 53:1143–1145
Thyroid Nodules with Benign Cytology: Is Size ‡4 cm an Indication for Surgery? Pedro Weslley Rosa´rio
Ó Socie´te´ Internationale de Chirurgie 2013
Recently, Wharry et al. [1] reported the malignancy rate for 382 thyroid nodules. First, except for purely cystic or autonomous nodules, fine-needle aspiration (FNA) is recommended for nodules C4 cm, irrespective of clinical history and ultrasonographic features [2]. Second, in these cases (non-autonomous nodules C4 cm), consensus exists regarding the indication for thyroidectomy if cytology is suspicious of malignancy, malignant, indeterminate, or non-diagnostic [2]. Therefore, considering these aspects (systematic indication for FNA and surgery when the cytology result is not benign), the results of that series [1] are in accordance with current recommendations [2]. Controversy exists regarding the proposal that patients with nodules C4 cm should be submitted to thyroidectomy even when cytology is benign [1]. This recommendation was based on a false-negative rate of 10 % for FNA [1]. One limitation of the study of Wharry et al. [1] is that the rate of malignancy was extracted from a subgroup of patients referred for thyroidectomy. It is reasonable to assume that this subgroup had characteristics of a higher risk for malignancy than the subgroup in which the clinicians decided to use observation. This pre-selection may have overestimated the rate of false-negative FNA results. It would therefore be necessary to evaluate all cases in order to define the true frequency of malignancy in nodules C4 cm with benign cytology. Analyzing the series of Table 5 in the article of Wharry et al. [1], the malignancy rates were also extracted from a subgroup of patients referred for surgery, except for two studies [3, 4]. In the
P. W. Rosa´rio (&) Endocrinology Service, Santa Casa de Belo Horizonte, Rua Domingos Vieira, 590, Santa Efigeˆnia, Belo Horizonte, Minas Gerais CEP 30150-240, Brazil e-mail: [email protected]
first study, Porterfield et al. [3] reported the evolution of 742 patients with nodules C3 cm with benign cytology: (i) of 145 nodules submitted to surgery, only one was malignant, and (ii) none of the more than 500 patients not submitted to thyroidectomy developed apparent malignancy after 3 years of follow-up. The second study was conducted at our service [4], where all patients with nodular disease are first seen by endocrinologists (patients have no direct access to surgeons) and those with nodules C4 cm were systematically referred for surgery after FNA. We showed that only 3 of 84 nodules C4 cm with benign cytology were malignant [4]. The results of these studies, the only ones reporting the evolution of all patients with large nodules with benign cytology and not only that of a subgroup submitted to surgery [3, 4], do not support the proposal that every nodule C4 cm should be removed [1]. Since Wharry et al. [1] did not evaluate nodules \4 cm, it is not possible to conclude that the false-negative rate of 10 % found for nodules C4 cm is due to the size of the nodules or is an inherent limitation of FNA. Analyzing the series of Table 5 in the article of Wharry et al. [1], we found that only six series compared the false-negative rate of FNA between larger versus smaller nodules and no difference was observed in four of them. Moreover, these four series together evaluated 464 large nodules with benign cytology, whereas the two series showing a higher false-negative rate of FNA for larger nodules together evaluated only 51 nodules. If it is not possible to ensure that the size of the nodule contributes to the false-negative rate of FNA, it does not seem to be reasonable to adopt this criterion for the indication of surgery in asymptomatic patients with benign cytology. Acknowledgments interest.
The author declares no potential conflicts of
123
World J Surg
References 1. Wharry LI, McCoy KL, Stang MT et al (2013) Thyroid nodules (C4 cm): can ultrasound and cytology reliably exclude cancer? World J Surg. doi:10.1007/s00268-013-2261-9 2. Cooper DS, Doherty GM, Haugen BR et al (2009) Revised American Thyroid Association management guidelines for patients with thyroid nodules and differentiated thyroid cancer. Thyroid 19:1167–1214
123
3. Porterfield JR Jr, Grant CS, Dean DS et al (2008) Reliability of benign fine needle aspiration cytology of large thyroid nodules. Surgery 144:963–968 discussion 968–969 4. Rosario PW, Salles DS, Bessa B et al (2009) Low false-negative rate of cytology in thyroid nodules C4 cm. Arq Bras Endocrinol Metabol 53:1143–1145
