{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,3]],"date-time":"2026-07-03T18:33:21Z","timestamp":1783103601909,"version":"3.54.6"},"reference-count":17,"publisher":"Springer Science and Business Media LLC","license":[{"start":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T00:00:00Z","timestamp":1774224000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T00:00:00Z","timestamp":1774224000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"name":"University of Kocaeli"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Virchows Arch"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Urothelial carcinoma (UC) of the urinary bladder comprises a heterogeneous group of histologic subtypes with distinct prognostic and therapeutic implications. Current World Health Organization (WHO) and International Society of Urological Pathology (ISUP) recommendations emphasize the recognition and reporting of UC subtypes, even when present as minor components. However, the practical application of these recommendations in routine diagnostic practice remains challenging, and interobserver variability persists. We conducted a cross-sectional, web-based survey to evaluate pathologists\u2019 awareness, diagnostic interpretation, and reporting practices regarding UC subtypes. The survey included 46 items encompassing demographics, conceptual knowledge, attitudes toward subtype reporting, and 39 image-based diagnostic questions covering a broad spectrum of UC subtypes. Reference standard diagnoses were established by consensus among genitourinary pathology experts. Agreement rates and patterns of diagnostic disagreement were analyzed descriptively. A total of 133 pathologists submitted responses, and 79 completed all survey items. The overall mean agreement rate with the reference standard across image-based questions was 65%. The highest levels of agreement with the reference standard were observed for micropapillary UC, lymphoepithelioma-like UC, and clear-cell (glycogen-rich) UC, whereas the lowest accuracy rates were seen for UC with trophoblastic differentiation, nested UC, and UC with glandular differentiation. A high level of diagnostic disagreement was noted among morphologically overlapping subtypes, particularly glandular, squamous, and large nested patterns. Despite these challenges, 94% of respondents reported that UC subtypes should be routinely documented, although substantial variability existed regarding threshold criteria for reporting. This survey demonstrates significant interobserver variability in the recognition and interpretation of urothelial carcinoma subtypes, especially for rare or morphologically overlapping variants. While certain subtypes show high diagnostic concordance, many remain within diagnostic gray zones that may affect reporting consistency and clinicopathologic communication. These findings underscore the need for continued education, refinement of consensus criteria, and practical guidance to improve diagnostic reproducibility and standardization in the reporting of UC subtypes.<\/jats:p>","DOI":"10.1007\/s00428-026-04488-0","type":"journal-article","created":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T07:46:27Z","timestamp":1774251987000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Interobserver variability in the recognition of urothelial carcinoma subtypes: a survey"],"prefix":"10.1007","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5779-6797","authenticated-orcid":false,"given":"Ganime","family":"Coban","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1660-3629","authenticated-orcid":false,"given":"Deniz","family":"Baycelebi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0537-3127","authenticated-orcid":false,"given":"Busra","family":"Yaprak Bayrak","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7747-0460","authenticated-orcid":false,"given":"Kemal","family":"Kosemehmetoglu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0929-0940","authenticated-orcid":false,"given":"Mahmut","family":"Akgul","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6619-6868","authenticated-orcid":false,"given":"Yasemin Yuyucu","family":"Karabulut","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,3,23]]},"reference":[{"key":"4488_CR1","doi-asserted-by":"publisher","first-page":"e11","DOI":"10.1097\/PAS.0000000000002077","volume":"48","author":"GP Paner","year":"2024","unstructured":"Paner GP, Kamat A, Netto GJ, Samaratunga H, Varma M et al (2024) International Society of Urological Pathology (ISUP) consensus conference on current \u0131ssues in bladder cancer. Working group 2: grading of mixed grade, invasive urothelial carcinoma including histologic subtypes and divergent differentiations, and non-urothelial carcinomas. Am J Surg Pathol 48:e11\u2013e23","journal-title":"Am J Surg Pathol"},{"key":"4488_CR2","doi-asserted-by":"publisher","first-page":"472","DOI":"10.1016\/j.eururo.2025.04.008","volume":"88","author":"CE Chu","year":"2025","unstructured":"Chu CE, Chen Z, Whiting K, Ostrovnaya I, Lenis AT et al (2025) Clinical outcomes, genomic heterogeneity, and therapeutic considerations across histologic subtypes of urothelial carcinoma. Eur Urol 88:472\u2013481","journal-title":"Eur Urol"},{"key":"4488_CR3","doi-asserted-by":"publisher","DOI":"10.1097\/mou.0000000000001358","author":"D Ertoy-Baydar","year":"2025","unstructured":"Ertoy-Baydar D (2025) Histologic subtypes of urothelial carcinoma: an update. 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Histopathology 85:748\u2013759","journal-title":"Histopathology"},{"key":"4488_CR6","doi-asserted-by":"publisher","first-page":"1367","DOI":"10.1097\/PAS.0b013e3181ec86b3","volume":"34","author":"AR Sangoi","year":"2010","unstructured":"Sangoi AR, Beck AH, Amin MB, Cheng L, Epstein JI et al (2010) Interobserver reproducibility in the diagnosis of invasive micropapillary carcinoma of the urinary tract among urologic pathologists. Am J Surg Pathol 34:1367\u20131376","journal-title":"Am J Surg Pathol"},{"key":"4488_CR7","doi-asserted-by":"publisher","first-page":"596.e9","DOI":"10.1016\/j.urolonc.2025.06.010","volume":"43","author":"BK Wallace","year":"2025","unstructured":"Wallace BK, Su ZT, Flynn JP, Garman TS, Weitzner A et al (2025) National trends in diagnoses of subtype histologies in bladder cancer: a population-based study based on the SEER database. Urol Oncol 43:596.e9-596.e13","journal-title":"Urol Oncol"},{"key":"4488_CR8","doi-asserted-by":"publisher","first-page":"564","DOI":"10.1097\/JU.0000000000003836","volume":"211","author":"Y Allory","year":"2024","unstructured":"Allory Y, Culine S, Krucker C, Fontugne J, Harter V, Pfister C (2024) Impact of divergent differentiation and\/or histological subtype of urothelial carcinoma on patient outcomes in the GETUG-AFU V05 VESPER trial. J Urol 211:564\u2013574","journal-title":"J Urol"},{"key":"4488_CR9","doi-asserted-by":"publisher","first-page":"141","DOI":"10.1093\/ajcp\/aqaf058","volume":"164","author":"SE Wobker","year":"2025","unstructured":"Wobker SE, Smith SC (2025) Urothelial carcinoma\u2014are we moving beyond \u201cdivergent differentiation\u201d and \u201chistologic subtype\u201d? 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Eur Urol Oncol 8:1126\u20131139","journal-title":"Eur Urol Oncol"}],"container-title":["Virchows Archiv"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s00428-026-04488-0.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1007\/s00428-026-04488-0","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s00428-026-04488-0.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T20:02:53Z","timestamp":1774296173000},"score":1,"resource":{"primary":{"URL":"https:\/\/link.springer.com\/10.1007\/s00428-026-04488-0"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,23]]},"references-count":17,"alternative-id":["4488"],"URL":"https:\/\/doi.org\/10.1007\/s00428-026-04488-0","relation":{},"ISSN":["0945-6317","1432-2307"],"issn-type":[{"value":"0945-6317","type":"print"},{"value":"1432-2307","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,23]]},"assertion":[{"value":"12 January 2026","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"26 February 2026","order":2,"name":"revised","label":"Revised","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"12 March 2026","order":3,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"23 March 2026","order":4,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"This study involved an anonymous survey of practicing pathologists and did not include\u00a0patient-level data or identifiable personal information. According to institutional and national\u00a0guidelines, formal ethics committee approval was not required. Completion of the survey was\u00a0considered to imply informed consent.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"The authors declare no competing interests.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}]}}