{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T18:30:00Z","timestamp":1774290600445,"version":"3.50.1"},"reference-count":14,"publisher":"Oxford University Press (OUP)","issue":"3","license":[{"start":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T00:00:00Z","timestamp":1774224000000},"content-version":"vor","delay-in-days":22,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,3,23]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Background: Atypical carcinoids (ACs) are uncommon neuroendocrine tumors of the lung, and the presence of a prominent mucinous stroma is an exceptionally rare feature that may complicate diagnosis. Highlighting such variants is important for avoiding misclassification with mucin-producing pulmonary tumors. Case Presentation: A 34-year-old nonsmoking female presented with mild chest pain, minimal cough, and night sweats. Imaging revealed a well-circumscribed right middle-lobe lesion measuring 4.1\u00a0cm, and bronchoscopy showed a white-tan, fleshy mass filling the bronchial lumen. Pathology Findings: Histologic examination demonstrated a well-defined neoplasm with organoid, trabecular, follicular, pseudopapillary, and solid patterns and striking mucinous stromal change. Immunohistochemical staining was positive for CK AE1\/AE3, synaptophysin (diffuse), chromogranin (diffuse), and TTF1, and negative for CK7, CK20, and CDX2. Focal necrosis and a mitotic rate of up to 5\/2\u00a0mm2 supported the diagnosis of AC. Conclusion: This case represents a rare morphologic variant of AC distinguished by a prominent mucinous stroma, a feature that may obscure the diagnosis by simulating other mucin-producing lung tumors. Recognizing this uncommon pattern is crucial, as it directly impacts diagnostic accuracy and subsequent clinical decision-making.<\/jats:p>","DOI":"10.1093\/omcr\/omag020","type":"journal-article","created":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T17:42:50Z","timestamp":1774287770000},"source":"Crossref","is-referenced-by-count":0,"title":["Atypical lung carcinoid with prominent mucinous stroma: unusual pathologic finding in pulmonary carcinoid"],"prefix":"10.1093","volume":"2026","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-0696-0408","authenticated-orcid":false,"given":"Ghaida S","family":"AlSugair","sequence":"first","affiliation":[{"name":"Department of Basic Sciences, College of Medicine, Princess Nourah Bint Abdulrahman University , Airport Road, P.O. Box 84428, Riyadh 11671 ,","place":["Kingdom of Saudi Arabia"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wajd A","family":"Althakfi","sequence":"additional","affiliation":[{"name":"Histopathology Unit, Department of Pathology, King Saud University , Diriyah Road, P.O. Box 2455 Riyadh 11451 ,","place":["Kingdom of Saudi Arabia"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"286","published-online":{"date-parts":[[2026,3,23]]},"reference":[{"key":"2026032313424383100_ref1","volume-title":"Thoracic tumours","author":"WHO Classification of Tumours Editorial Board","year":"2021","edition":"5"},{"key":"2026032313424383100_ref2","doi-asserted-by":"publisher","first-page":"381","DOI":"10.1007\/s12254-021-00681-w","article-title":"Neuroendocrine neoplasms of the lung: a pathology update","volume":"14","author":"Metovic","year":"2021","journal-title":"Memo"},{"key":"2026032313424383100_ref3","doi-asserted-by":"publisher","first-page":"1218","DOI":"10.1136\/jcp.31.12.1218","article-title":"Mucin-producing atypical bronchial carcinoid","volume":"31","author":"Sweeney","year":"1978","journal-title":"J Clin Pathol"},{"key":"2026032313424383100_ref4","doi-asserted-by":"publisher","first-page":"120","DOI":"10.1007\/s12022-010-9115-x","article-title":"Atypical carcinoid with prominent mucinous stroma: a hitherto unreported variant of pulmonary neuroendocrine tumor","volume":"21","author":"Nannini","year":"2010","journal-title":"Endocr Pathol"},{"key":"2026032313424383100_ref5","doi-asserted-by":"publisher","first-page":"114","DOI":"10.1016\/j.anndiagpath.2005.07.017","article-title":"Thymic carcinoid with mucinous stroma: a rare variant of carcinoid with an aggressive clinical course","volume":"10","author":"Gao","year":"2006","journal-title":"Ann Diagn Pathol"},{"key":"2026032313424383100_ref6","doi-asserted-by":"publisher","first-page":"1277","DOI":"10.1097\/00000478-199511000-00008","article-title":"Thymic carcinoid with prominent mucinous stroma","volume":"19","author":"Suster","year":"1995","journal-title":"Am J Surg Pathol"},{"key":"2026032313424383100_ref7","doi-asserted-by":"publisher","DOI":"10.1530\/ERC-20-0253","article-title":"Stromal changes in neuroendocrine tumors: biological and prognostic implications","volume":"27","author":"Perren","year":"2020","journal-title":"Endocr Relat Cancer"},{"key":"2026032313424383100_ref8","doi-asserted-by":"publisher","DOI":"10.1007\/s00428-021-03211-5","article-title":"Neuroendocrine neoplasms of the pancreas and gastrointestinal tract: morphology and stroma interaction","volume":"480","author":"Kl\u00f6ppel","year":"2021","journal-title":"Virchows Arch."},{"key":"2026032313424383100_ref9","doi-asserted-by":"publisher","DOI":"10.1186\/s12943-023-01744-8","volume":"22","author":"Yuan","year":"2023","journal-title":"Mol Cancer"},{"key":"2026032313424383100_ref10","author":"Lan"},{"key":"2026032313424383100_ref11","first-page":"473","article-title":"Mucin-rich tumors of the lung","volume":"127","author":"Rossi","year":"2007","journal-title":"Am J Clin Pathol"},{"key":"2026032313424383100_ref12","doi-asserted-by":"publisher","DOI":"10.1002\/cncr.23048","volume":"110","author":"","year":"2007","journal-title":"Cancer"},{"key":"2026032313424383100_ref13","doi-asserted-by":"publisher","first-page":"510","DOI":"10.3390\/cancers10120510","article-title":"Management of typical and atypical pulmonary carcinoids based on different established guidelines","volume":"10","author":"Gosain","year":"2018","journal-title":"Cancers (Basel)"},{"key":"2026032313424383100_ref14","doi-asserted-by":"publisher","DOI":"10.1016\/j.annonc.2020.03.304","volume":"31","author":"","year":"2020","journal-title":"Annals of Oncology"}],"container-title":["Oxford Medical Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/omcr\/article-pdf\/2026\/3\/omag020\/67483596\/omag020.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/omcr\/article-pdf\/2026\/3\/omag020\/67483596\/omag020.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T17:42:51Z","timestamp":1774287771000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/omcr\/article\/doi\/10.1093\/omcr\/omag020\/8537680"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3]]},"references-count":14,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2026,3,23]]}},"URL":"https:\/\/doi.org\/10.1093\/omcr\/omag020","relation":{},"ISSN":["2053-8855"],"issn-type":[{"value":"2053-8855","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2026,3]]},"published":{"date-parts":[[2026,3]]},"article-number":"omag020"}}