{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T18:02:28Z","timestamp":1790100148688,"version":"4.0.1"},"reference-count":21,"publisher":"SAGE Publications","license":[{"start":{"date-parts":[[2026,9,19]],"date-time":"2026-09-19T00:00:00Z","timestamp":1789776000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Int J Surg Pathol"],"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To report a rare lesion, an intra-articular extra-synovial venous-type synovial haemangioma of the knee in a young adult and to review the relevant literature on this frequently misdiagnosed entity.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Case report<\/jats:title>\n                    <jats:p>A 21-year-old man presented with recurrent knee effusions and pain over several years. Imaging studies revealed a well-defined, intra-articular, extra-synovial soft-tissue mass located in the anteromedial compartment of the knee. Magnetic resonance imaging (MRI) demonstrated multiple tubular structures with high signal intensity on T2- and short tau inversion recovery (STIR)-weighted images and intense, homogeneous contrast enhancement, consistent with a vascular lesion. Surgical excision was performed, and histopathological analysis confirmed a venous-type synovial haemangioma, characterized by large-calibre vascular channels lined by bland endothelial cells and containing organizing thrombi. The postoperative course was uneventful, and the patient remained disease-free at 6 months of follow-up.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Synovial haemangioma, though rare, should be considered in the differential diagnosis of recurrent knee effusions in young patients. It may mimic other benign or malignant periarticular lesions. MRI plays a key role in the evaluation, and the diagnosis can be strongly suggested by imaging, but histopathological confirmation remains essential for accurate characterization and appropriate management.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1177\/10668969261478601","type":"journal-article","created":{"date-parts":[[2026,9,19]],"date-time":"2026-09-19T13:52:57Z","timestamp":1789825977000},"update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":0,"title":["Intra-Articular Extra-Synovial Venous-Type Synovial Haemangioma of the Knee in a Young Adult: Case Report and Literature Review of This Frequently Misdiagnosed Lesion"],"prefix":"10.1177","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7113-045X","authenticated-orcid":false,"given":"Eva Manuela","family":"Pena-Burgos","sequence":"first","affiliation":[{"name":"Gregorio Mara\u00f1\u00f3n General University Hospital"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ignacio","family":"Mill\u00e1n Arredondo","sequence":"additional","affiliation":[{"name":"Gregorio Mara\u00f1\u00f3n General University Hospital"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mathilde de Andrade","family":"da Costa Gloria","sequence":"additional","affiliation":[{"name":"Gregorio Mara\u00f1\u00f3n General University Hospital"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alfonso","family":"Tejerizo Garc\u00eda","sequence":"additional","affiliation":[{"name":"Nuestra Se\u00f1ora de Sonsoles Hospital"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"F\u00e9lix Jes\u00fas","family":"Mora Ala\u00f1\u00f3n","sequence":"additional","affiliation":[{"name":"Gregorio Mara\u00f1\u00f3n General University Hospital"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jose Juan","family":"Pozo-Kreilinger","sequence":"additional","affiliation":[{"name":"La Paz University Hospital"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mar","family":"Tapia-Vi\u00f1e","sequence":"additional","affiliation":[{"name":"La Paz University Hospital"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2026,9,19]]},"reference":[{"issue":"379","key":"e_1_3_2_2_2","article-title":"Tumeur erectile de I\u2019articttlation du genou","volume":"29","author":"Bouchut E.","year":"1856","unstructured":"Bouchut E. 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