{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T18:25:53Z","timestamp":1777487153116,"version":"3.51.4"},"reference-count":32,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T00:00:00Z","timestamp":1777334400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Surg."],"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To evaluate the feasibility of transrectal ultrasound (TRUS) in the sonographic characterization and preoperative assessment of rectal neuroendocrine neoplasms (NENs).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Retrospective analysis was performed on the transrectal ultrasound manifestations and clinical data of 17 patients with pathologically and immunohistochemically confirmed rectal NENs [8 cases of rectal neuroendocrine tumors [NETs, G1\/G2] and 9 cases of rectal neuroendocrine carcinomas [NECs, G3]] between June 2020 and June 2025. These TRUS findings were compared with the ultrasound features of 31 contemporaneous cases of middle- and lower-segment rectal cancer.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      All 8 rectal NETs (G1, G2) showed hypoechoic masses in the rectal mucosal and submucosal layers on TRUS, with clear borders in 8 cases, point-stripe blood flow signals in 7 cases, and round-shaped lymph nodes with a short diameter &amp;gt; 5\u2005mm in 3 cases; contrast-enhanced ultrasound (CEUS) was performed in 6 cases, showing inhomogeneous hyperenhancement in 2 cases and homogeneous isoenhancement in 4 cases. Among the 9 rectal NECs (G3), 8 presented with localized irregular thickening of the rectal wall, 7 invaded perirectal tissues or organs, all lesions were hypoechoic or heteroechoic with muscularis propria infiltration, and 4 cases had enlarged local lymph nodes. Compared with rectal cancer, the distribution of T stage (T1 vs. T2\u20134) differed significantly (\n                      <jats:italic>P<\/jats:italic>\n                      \u2009=\u20090.016), whereas no significant differences were noted in gender, age, distance from the lower margin of the lesion to the intersphincteric sulcus, lesion length, lesion thickness, or N stage (all\n                      <jats:italic>P<\/jats:italic>\n                      \u2009&amp;gt;\u20090.05). The overall concordance rate between ultrasonographic staging and surgical pathological staging was 70.6% (12\/17) for all rectal NENs, with 87.5% (7\/8) for NETs and 55.6% (5\/9) for NECs. A limitation of this retrospective feasibility study is its relatively small sample size (\n                      <jats:italic>n<\/jats:italic>\n                      \u2009=\u200917), which needs further verification in future multi-center large-sample studies.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Rectal NETs exhibit characteristic TRUS manifestations and require differentiation from polyps, adenocarcinomas, and inflammatory lesions. Transrectal contrast-enhanced ultrasonography (TR-CEUS), though not widely adopted, is feasible for the preoperative assessment of rectal NENs and may be valuable for follow-up after endoscopic resection to monitor recurrence.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fsurg.2026.1801458","type":"journal-article","created":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T14:33:43Z","timestamp":1777386823000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Case Report: Transrectal contrast-enhanced ultrasonography on preoperative evaluation of rectal neuroendocrine tumors: a 17-case preliminary study"],"prefix":"10.3389","volume":"13","author":[{"given":"Jigang","family":"Jing","sequence":"first","affiliation":[{"name":"Department of Ultrasound Medicine, West China Hospital of Sichuan University","place":["Chengdu, Sichuan, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuting","family":"Wu","sequence":"additional","affiliation":[{"name":"Department of Ultrasound Medicine, West China Hospital of Sichuan University","place":["Chengdu, Sichuan, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hua","family":"Zhuang","sequence":"additional","affiliation":[{"name":"Department of Ultrasound Medicine, West China Hospital of Sichuan University","place":["Chengdu, Sichuan, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,4,28]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"165","DOI":"10.1186\/s12876-022-02237-6","article-title":"Can transrectal ultrasonography distinguish anorectal malignant melanoma from low rectal adenocarcinoma? 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