Thyroid nodules with isolated macrocalcification: malignancy risk and diagnostic efficacy of fine-needle aspiration and core needle biopsy

Abstract

Purpose:This study was performed to determine the malignancy risk of thyroid nodules with isolated macrocalcification and to evaluate the diagnostic efficacy of fine-needle aspiration (FNA) and core needle biopsy (CNB).Methods:From May 2008 to December 2014, a total of 44 patients with isolated macrocalcifications were enrolled from 4,081 consecutive patients who underwent FNA or CNB at a single institution. We assessed the malignancy risk of nodules with isolated macrocalcification. We compared the diagnostic results between FNA and CNB, and the diagnostic efficacy of each procedure was evaluated by the rate of inconclusive results. We compared the diagnostic performance for malignancy between FNA and CNB with a criterion of malignant or atypia/follicular lesion of undetermined significance (indeterminate) diagnostic results. We investigated whether the ultrasonographic feature of isolated macrocalcification was predictive of malignancy.Results:The malignancy risk of nodules with isolated macrocalcification was 16.1% in 31 nodules with final diagnoses and 11.4% in all nodules. CNB demonstrated a significantly lower rate of nondiagnostic and inconclusive results than FNA (7.7% vs. 53.8%, P=0.002 and 15.4% vs. 57.7%, P=0.003, respectively) in 26 nodules that underwent both FNA and CNB. CNB showed a marginally higher diagnostic performance for identifying malignancy than FNA (P=0.067). The ultrasonographic features of the anterior margin of isolated macrocalcification were not predictive of malignancy (P>0.999).Conclusion:Thyroid nodules with isolated macrocalcification had a low to intermediate malignancy risk and should not be considered benign nodules. CNB showed a higher diagnostic efficacy than FNA in these nodules.

Core Needle Biopsy of the Thyroid: 2016 Consensus Statement and Recommendations from Korean Society of Thyroid Radiology

“…Sometimes, the nodule is so hard that the needle may be deflected and damage adjacent structures. Thus, before sampling hard nodules, careful evaluation of the surrounding structures is vital (363753). …”

“…Restriction of free needle movement during FNA may hinder the collection of adequate and accurate cytological specimens from calcified nodules. CNB has a technical failure rate of 1.1% for the collection of tissue from dense calcified thyroid nodules and a non-diagnostic rate of 0.7–7.7% and could prevent unnecessary diagnostic surgery (363753). CNB obtains fewer inconclusive diagnoses than FNA and could minimize the need for diagnostic surgery in patients with calcified thyroid nodules (3653).…”

CT features of thyroid nodules with isolated macrocalcifications detected by ultrasonography

“…The enrolled patients were selected from 82 patients with isolated macrocalcifications detected by US at two institutions. Forty-four patients with isolated macrocalcifications were found in the cohort data (dataset 1, n=4,081) of patients with thyroid nodules at one institution; details about this cohort have previously been published [6]. Thirtyeight patients with isolated macrocalcifications were found in the cohort data (dataset 2, n=3,061) of patients with thyroid nodules in whom fine-needle aspiration (FNA) or core needle biopsy (CNB) was performed from January 2011 to June 2018 at another institution.…”

“…Meanwhile, computed tomography (CT) has the advantage of enabling detailed evaluations of isolated macrocalcifications. A previous study [6] reported that isolated macrocalcifications may present as entirely calcified nodules on CT; however, there has been little research into the CT features of isolated macrocalcifications. Therefore, this study aimed to determine the CT features of thyroid nodules with isolated macrocalcifications detected by US.…”

“…Although macrocalcifications may be Ultrasonography 39(2), April 2020 e-ultrasonography.org associated with an increased risk of malignancy, the malignancy rate in nodules with macrocalcifications has been found to be highly variable, meaning that macrocalcifications are not a highly specific predictor of malignancy [2][3][4][5]. An isolated macrocalcification is defined as a calcified nodule with complete posterior acoustic shadowing in which no soft tissue component can be identified due to dense shadowing on US [6]. A US lexicon for isolated macrocalcifications has not been established, and the presence of isolated macrocalcifications has only been considered as part of the risk stratification of nodules in the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) [7,8] and in the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) [8][9][10].…”