Diagnostic accuracy of multiparametric ultrasound for peripheral nerve schwannoma

Abstract

Background Ultrasound (US) diagnostic techniques have the advantages of low cost, convenient operation, and high availability. Purpose To explore the diagnostic accuracy of multiparametric US in evaluating signs of peripheral schwannoma. Material and Methods This retrospective case-control study included patients with soft-tissue masses on the limbs (divided into the schwannoma and non-schwannoma groups) between January 2017 and November 2020. US features were compared between the two groups, and receiver operating characteristics analysis was used to evaluate the diagnostic efficacy of these features. Results A total of 165 patients were included in this study; of them, 63 (38.2%) were diagnosed with schwannoma. Regular morphology (95.2% vs. 39.2%), cystic degeneration (71.4% vs. 27.5%), target sign on elastography (82.5% vs. 0), and polar blood supply sign (87.3% vs. 14.7%) were more common in schwannomas than in non-schwannoma lesions (all P < 0.001). Combining the four signs for diagnosis of schwannomas, the sensitivity, specificity, and accuracy were 95.24%, 96.08%, and 95.76%, respectively, with an area under the curve (AUC) of 0.987 (95% confidence interval = 0.955–0.998). Entering and exiting nerve sign was observed in 87.3% of schwannomas and in 3.0% of non-schwannoma lesions ( P < 0.001), while split-fat sign was similar between the two groups (9.5% vs. 2.0%; P = 0.068). Conclusion Polar blood supply sign and target sign on elastography are specific US signs in peripheral schwannomas. The combination of two-dimensional imaging, color flow imaging, and elastography can achieve an excellent diagnostic accuracy in schwannomas.

An Update on Clinicopathological, Imaging, and Genetic Features of Angioleiomyoma

“…Ultrasound typically shows a well-defined hypoechoic mass with variable posterior acoustic enhancement (24). An entering and exiting nerve sign and a polar blood supply sign on color doppler flow imaging can be seen (25). Ogata et al reported that several ultrasonographic features including maximum diameter, tumor localization and continuity with the nerve were significantly different between schwannoma and angioleiomyoma (26).…”

Multiparametric ultrasound images of three different cases of schwannoma of the peripheral nervous system

“…In order to facilitate the work of the sonographer, diagnostic signs have been found such as “regular morphology, cystic degeneration, polar blood supply sign, target sign” that, when simultaneously present, allow the diagnosis with a sensitivity and specificity of 95.24% and 96.08%, respectively 2 …”

“…In order to facilitate the work of the sonographer, diagnostic signs have been found such as "regular morphology, cystic degeneration, polar blood supply sign, target sign" that, when simultaneously present, allow the diagnosis with a sensitivity and specificity of 95.24% and 96.08%, respectively. 2 Today, thanks to the considerable advancement of ultrasound technology, it is also possible to make use of many applications such as SMI (superb microvascular imaging) and 2D SWE (shear wave elastography) [3][4][5] ; they promise to provide increasingly accurate information about vascularity and elasticity, respectively, thus allowing a better definition and easier diagnostic recognition of the lesion.…”