Dear Editor,
Recently, Russ et al. [1] endorsed active surveillance for low-risk papillary microcarcinoma of the thyroid (PMT). It is also reasonable to imagine that, if immediate treatment is not necessary, fine-needle aspiration (FNA) of corresponding nodules ≤1 cm could be postponed until therapy is considered. This is the recommendation of the European Thyroid Association (ETA) [1] and American Thyroid Association (ATA) [2].
Although I agree that active surveillance is an option for low-risk PMT, I believe that FNA should precede this decision. At our institution, nodules with highly suspicious features on ultrasonography (US) are always submitted to FNA (irrespective of size) and the latter is repeated when cytology is commenced [3, 4]. We revised 181 patients with 198 nodules ≤1 cm that were highly suspicious and apparent ly restricted to the thyroid on US [5]. The initial cytology was benign in 76 nodules (38.4%), in which the repetition of FNA confirmed the benign nature in 59 (29.8%). Thus, FNA changed the “presumptive” diagnosis of PMT in 30% of the nodules [5].
For nodules ≤1 cm with highly suspicious US features and not submitted to FNA, Russ et al. [1] recommend regular US scanning. In fact, this is the protocol adopted by the centers with the largest experience in active surveillance of PMT. In contrast, for nodules submitted to FNA and with a benign cytology, the ATA and ETA recommend the repetition of FNA [1, 2] but follow-up with US is no longer necessary after 2 benign cytology results [2]. Since the recommendation is general [2], there is more reason to assume that it applies to nodules ≤1 cm. In addition to this relevant difference in follow-up, with the omission of FNA, a significant proportion of patients (about 30% in our series) would be unnecessarily and equivocally submitted to the psychological stress of having a presumptive diagnosis of “cancer” or of a “nodule with a high probability of cancer.”
In my opinion, the consequences cited above, together with the fact that FNA is a widely available, low-cost, and safe procedure, favor its use before deciding on the active surveillance of nodules ≤1 cm with highly suspicious US features that are sporadic and apparently restricted to the thyroid. Although rare, FNA may detect uncommon tumors (such as medullary carcinoma or aggressive variants of papillary thyroid cancer) that are not candidates for active surveillance [2].
Disclosure Statement
No competing financial interests exist.
Footnotes
verified
References
- 1↑
Russ G, Bonnema SJ, Erdogan MF, Durante C, Ngu R, Leenhardt L: European Thyroid Association guidelines for ultrasound malignancy risk stratification of thyroid nodules in adults: The EU-TIRADS. Eur Thyroid J 2017; 6: 225–237.
- 2↑
Haugen BR, Alexander EK, Bible KC, et al: 2015 American Thyroid Association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid 2016; 26: 1–133.
- 3↑
Rosario PW, Purisch S: Ultrasonographic characteristics as a criterion for repeat cytology in benign thyroid nodules. Arq Bras Endocrinol Metabol 2010; 54: 52–55.
- 4↑
Rosario PW, Calsolari MR: What is the best criterion for repetition of fine-needle aspiration in thyroid nodules with initially benign cytology? Thyroid 2015; 25: 1115–1120.
- 5↑
Rosario PW, Silva AL, Calsolari MR: Is fine needle aspiration really not necessary in patients with thyroid nodules ≤1 cm with highly suspicious features on ultrasonography and candidates for active surveillance? Diagn Cytopathol 2017; 45: 294–296.
