1Department of Endocrinology and Metabolism, Ankara University, School of Medicine, Ankara, Turkey.
2Department of Endocrinology and Metabolism, Ankara Guven Hospital, Ankara, Turkey.
Eur Thyroid J. 2023 Dec 28;12(6). doi: 10.1530/ETJ-23-0108. Print 2023 Dec 1.
Punctate echogenic foci (PEF)/microcalcifications are thought to represent psammoma bodies (PB) in histopathology. However, there are few and contradictory data on this. Different types of sonographic echogenic microfoci (EMF) are seen in papillary thyroid carcinoma (PTC), and their histopathological equivalents are not clearly known. There is also conflicting data on the interobserver agreement between the sonographers on EMF.
We prospectively collected US video records of PTC nodules with and without EMF in two large thyroid centers. All video recordings were independently interpreted by three blinded, experienced sonographers. EMF were classified as true microcalcifications (punctate echogenic foci (PEF) ≤1 mm long), linear microechogenities (>1 mm long, posterior acoustic enhancement of the back wall of a microcystic area), comet-tail artifacts/reverberations or linear microechogenities with comet-tail artifacts/reverberations, non-shadowing coarse echogenic foci (>1 mm nonlinear areas) and unclassifiable. Histopathological evaluation was performed by two blinded, qualified pathologists.
A total of 114 malignant nodules were included. The average Cohen's kappa (κ) of three sonographers for the EMF presence was 0.775, indicating substantial agreement. A substantial agreement for PEF with 0.658 κ, only fair agreement for other types of EMF with 0.052 to 0.296 κ were detected. EMF were significantly associated with PB and papillae. PEF had an evident relationship with PB in multivariate analysis. There was a strong positive correlation between the amount of PEF and PB (r = 0.634, P < 0.001).
PEF in PTC mainly correspond to PB on histopathology. Although observation of EMF varies among sonographers, this inconsistency can be reduced by classifying EMF into subgroups and keeping the term 'PEF' only for true microcalcifications.
点状强回声灶（PEF）/微钙化被认为代表组织病理学中的沙粒体（PB）。然而，关于这一点的数据很少且存在矛盾。甲状腺乳头状癌（PTC）中可见不同类型的超声回声微灶（EMF），但其组织病理学等同物尚不清楚。超声医师对 EMF 的观察结果之间的观察者间一致性也存在矛盾数据。
我们前瞻性地收集了两家大型甲状腺中心的 PTC 结节的 US 视频记录，这些结节有或没有 EMF。所有视频记录均由三名经验丰富的盲法超声医师独立解读。将 EMF 分类为真正的微钙化（点状强回声灶（PEF）≤1 毫米长）、线性微回声（>1 毫米长，微囊性区域后壁的后向声增强）、彗尾伪像/回声或具有彗尾伪像/回声的线性微回声、非阴影状粗回声灶（>1 毫米非线性区域）和无法分类。组织病理学评估由两名盲法、合格的病理学家进行。
共纳入 114 个恶性结节。三名超声医师对 EMF 存在的平均 Cohen's kappa（κ）为 0.775，表明存在显著一致性。PEF 的 κ 值为 0.658，一致性较好，而其他类型的 EMF 的 κ 值为 0.052 至 0.296，一致性仅为一般。EMF 与 PB 和乳头显著相关。PEF 在多变量分析中与 PB 有明显的关系。PEF 的数量与 PB 之间存在强烈的正相关（r = 0.634，P <0.001）。
PTC 中的 PEF 主要对应于组织病理学上的 PB。尽管超声医师对 EMF 的观察存在差异，但通过将 EMF 分为亚组，并仅将术语“PEF”保留用于真正的微钙化，可以减少这种不一致性。
