Signet-ring cell carcinoma (SRCC) of ampulla of Vater is extremely uncommon, and less than 15 cases have been reported so far in literature. It mainly occurs in elderly people (median age 57 years). We report a rare case of SRCC of the ampulla of Vater in a 38-year-old woman who presented with a small tumor at the Vater, discovered by the contrast-enhanced ultrasound (CEUS). Histopathological examination showed prominent signet-ring features. We also describe the imaging features of SRCC of ampulla of Vater in CEUS.

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.

Objective To explore the effect of locating the ulnar nerve compression sites and guiding the small incision so as to decompress the ulnar nerve in situ on the elbow by high‐frequency ultrasound before operation. Methods A retrospective analysis was conducted on 56 patients who underwent ultrasound‐assisted in situ decompression for cubital tunnel syndrome from May 2018 to August 2019. The patients' average age was 51.13 ± 7.35 years, mean duration of symptoms was 6.51 ± 1.96 months, and mean postoperative follow‐up was 6.07 ± 0.82 months. Nine patients had Dellon's stage mild, 39 had stage moderate, and eight had stage severe. Ultrasound and electromyography were completed in all patients before operation. The presence of ulnar nerve compressive lesion, the specific location, and the reason and extent of compression were determined by ultrasound. A small incision in situ surgery was given to decompress the ulnar nerve according to the pre‐defined compressive sites. Results All patients underwent in situ decompression. The compression sites around the elbow were as follows: two in the arcade of Struthers, one in the medial intermuscular septum, four in the anconeus epitrochlearis muscle, five beside the cyst of the proximal flexor carpi ulnaris (FCU), and the remaining 44 cases were all from the compression between Osborne's ligament to the two heads of the FCU. The compression localizations diagnosed by ultrasound were confirmed by operations. Preoperative ultrasound confirmed no ulnar nerve subluxation in all cases. The postoperative outcomes were satisfactory. There was no recurrence or aggravation of symptoms in this group of patients according to the modified Bishop scoring system; results showed that 43 cases were excellent, 10 were good, and three were fair. Conclusions High‐frequency ultrasound can accurately and comprehensively evaluate the ulnar nerve compression and the surrounding tissues, thus providing significant guidance for the precise minimally invasive treatment of ulnar nerve compression.