{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T01:27:46Z","timestamp":1760059666981,"version":"build-2065373602"},"reference-count":13,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2025,6,28]],"date-time":"2025-06-28T00:00:00Z","timestamp":1751068800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Pulmonary neuroendocrine proliferations and neoplasms represent a broad spectrum of diseases, ranging from neuroendocrine cell hyperplasia and tumorlets to carcinoid tumors. Carcinoid tumorlets are most commonly located in the peripheral airways and are often incidentally detected as pulmonary micronodules on chest CT. We report the radiological, bronchoscopic, and pathological findings of a case of carcinoid tumorlets presenting as endobronchial nodules in the left main bronchus. The patient had previously undergone a left lower lobectomy five years earlier for a typical carcinoid tumor. Follow-up imaging revealed new endobronchial nodules, which were subsequently confirmed as carcinoid tumorlets through histopathologic analysis. This case highlights the rare presentation of carcinoid tumorlets in the central airways, emphasizing the importance of recognizing their potential for late recurrence and atypical localization. It underscores the necessity for physicians to be aware that pulmonary neuroendocrine tumors can recur over the long term and may present in a multicentric fashion within the disease spectrum.<\/jats:p>","DOI":"10.3390\/diagnostics15131651","type":"journal-article","created":{"date-parts":[[2025,6,30]],"date-time":"2025-06-30T05:00:37Z","timestamp":1751259637000},"page":"1651","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Central Airway Carcinoid Tumorlets Following Resection of a Typical Carcinoid Tumor"],"prefix":"10.3390","volume":"15","author":[{"given":"Kyungsoo","family":"Bae","sequence":"first","affiliation":[{"name":"Department of Radiology, Institute of Medical Science, School of Medicine, Gyeongsang National University, Jinju 52727, Republic of Korea"},{"name":"Department of Radiology, Gyeongsang National University Changwon Hospital, Changwon 51472, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2267-0366","authenticated-orcid":false,"given":"Kyung Nyeo","family":"Jeon","sequence":"additional","affiliation":[{"name":"Department of Radiology, Institute of Medical Science, School of Medicine, Gyeongsang National University, Jinju 52727, Republic of Korea"},{"name":"Department of Radiology, Gyeongsang National University Changwon Hospital, Changwon 51472, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5832-5233","authenticated-orcid":false,"given":"I Re","family":"Heo","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, School of Medicine, Gyeongsang National University, Gyeongsang National University Changwon Hospital, Changwon 51472, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hyo Jung","family":"An","sequence":"additional","affiliation":[{"name":"Department of Pathology, School of Medicine, Gyeongsang National University, Gyeongsang National University Changwon Hospital, Changwon 51472, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7163-0403","authenticated-orcid":false,"given":"Dae Hyun","family":"Song","sequence":"additional","affiliation":[{"name":"Department of Pathology, School of Medicine, Gyeongsang National University, Gyeongsang National University Changwon Hospital, Changwon 51472, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Noguchi, M., Furukawa, K.T., and Morimoto, M. (2020). Pulmonary neuroendocrine cells: Physiology, tissue homeostasis and disease. Dis. Model. Mech., 13.","DOI":"10.1242\/dmm.046920"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Granberg, D., Juhlin, C.C., Falhammar, H., and Hedayati, E. (2023). Lung Carcinoids: A Comprehensive Review for Clinicians. Cancers, 15.","DOI":"10.3390\/cancers15225440"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1038\/s41379-021-00943-2","article-title":"Lung neuroendocrine neoplasms: Recent progress and persistent challenges","volume":"35","author":"Rekhtman","year":"2022","journal-title":"Mod. Pathol."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Sun, T.Y., Hwang, G., Pancirer, D., Hornbacker, K., Codima, A., Lui, N.S., Raj, R., Kunz, P., and Padda, S.K. (2022). Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: Clinical characteristics and progression to carcinoid tumour. Eur. Respir. J., 59.","DOI":"10.1183\/13993003.01058-2021"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"293","DOI":"10.2214\/ajr.183.2.1830293","article-title":"Pulmonary tumorlets: CT findings","volume":"183","author":"Ginsberg","year":"2004","journal-title":"Am. J. Roentgenol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1635","DOI":"10.1378\/chest.06-2788","article-title":"Significance of multiple carcinoid tumors and tumorlets in surgical lung specimens: Analysis of 28 patients","volume":"131","author":"Aubry","year":"2007","journal-title":"Chest"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Maki, Y., Okada, K., Nakamura, R., Hirano, Y., Fujiwara, T., Yamasaki, R., Ichimura, K., and Matsuura, M. (2022). A case of multiple lung carcinoid tumors localized in the right lower lobe. Respir. Med. Case Rep., 38.","DOI":"10.1016\/j.rmcr.2022.101679"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1613","DOI":"10.1097\/JTO.0b013e318221f54f","article-title":"Tumorlets in familial history of bronchopulmonary carcinoid","volume":"6","author":"Fanini","year":"2011","journal-title":"J. Thorac. Oncol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"990","DOI":"10.4067\/S0717-95022022000400990","article-title":"An Unusual Finding of Tumorlet Carcinoid and Endobronchial Hamartoma in the Lobar Bronchus","volume":"40","author":"Popovic","year":"2022","journal-title":"Int. J. Morphol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"33","DOI":"10.4103\/jacp.jacp_55_23","article-title":"Carcinoid tumorlet\/typical carcinoid of the lung: An incidental bronchoscopic finding and cytological dilemma","volume":"12","author":"Pandey","year":"2024","journal-title":"J. Assoc. Chest Physicians"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1097\/JTO.0b013e318197f2e7","article-title":"Tumorlets, multicentric carcinoids, lymph-nodal metastases, and long-term behavior in bronchial carcinoids","volume":"4","author":"Ferolla","year":"2009","journal-title":"J. Thorac. Oncol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1016\/j.annonc.2021.01.003","article-title":"Lung and thymic carcinoids: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up","volume":"32","author":"Baudin","year":"2021","journal-title":"Ann. Oncol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1016\/j.lungcan.2020.03.027","article-title":"Whole-exome and RNA sequencing of pulmonary carcinoid reveals chromosomal rearrangements associated with recurrence","volume":"145","author":"Miyanaga","year":"2020","journal-title":"Lung Cancer"}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/15\/13\/1651\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:00:41Z","timestamp":1760032841000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/15\/13\/1651"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,28]]},"references-count":13,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2025,7]]}},"alternative-id":["diagnostics15131651"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics15131651","relation":{},"ISSN":["2075-4418"],"issn-type":[{"type":"electronic","value":"2075-4418"}],"subject":[],"published":{"date-parts":[[2025,6,28]]}}}