Ultrasonographic assessment and differentiation of spontaneous degenerating cystic thyroid nodules and papillary thyroid carcinomas / 中华耳鼻咽喉头颈外科杂志

ABSTRACT

Objective: To analyze the features of degenerating cystic thyroid nodules (DCTN) on conventional ultrasound and contrast-enhanced ultrasound (CEUS), and to explore the differentiation between DCTN and papillary thyroid carcinomas (PTC). Methods: A total of 46 DCTN (39 cases, including 12 males and 27 females, with an age range of 25 to 76 years) and 36 PTC (32 cases, including 8 males and 24 females, with an age range of 23 to 68 years) diagnosed via fine- needle aspiration (FNA) or surgery from February 2019 to January 2020 in the First Affiliated Hospital of Nanchang University were enrolled. The size, shape, margin, echogenicity, presence of shadowing, calcification and vascularity of DCTN and PTC were retrospectively evaluated, and 28 DCTN and 30 PTC underwent CEUS were separately analyzed and compared.The t test, χ² test or Fisher's exact test were implemented to compare the features of ultrasound among the two groups. The binary Logistic regression test was performed to determine whether the feature whose difference was statistically significant was an independent predictive risk factor. Results: A univariate analysis indicated that DCTN more frequently showed wider-than-tall shapes, marked hypoechogenicity, well-defined margin and no or dot-lined enhancement (wider-than-tall shapes 36 vs. 17, χ2=8.511; well-defined margin 30 vs. 15, χ2=4.523; marked hypoechogenicity 27 vs. 9, χ2=9.310; no or dot-lined enhancement 24 vs. 3, χ2=33.369; all P＜0.05). A multivariate analysis demonstrated that wider-than-tall shapes, well-defined margin and marked hypoechogenicity were independent predictors for DCTN (OR values were 5.204, 3.134 and 5.042, P values were 0.003, 0.031, and 0.003, respectively). Among 28 DCTN, 15 showed a decrease in mean maximum diameter (24.3±11.4 mm) with a mean time span of (18.6±10.5) months between the presence and absence of suspicious ultrasound features. Conclusions: Compared with PTC, DCTN shows the ultrasound characteristics of wider-than-tall shapes, well-defined margin, marked hypoechogenicity and no or dot-lined enhancement pattern. Ultrasound follow-up can help to identify spontaneous DCTN.