{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T15:37:05Z","timestamp":1791387425433,"version":"4.3.3"},"reference-count":13,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T00:00:00Z","timestamp":1772150400000},"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. Oncol."],"abstract":"<jats:p>\n                    Langerhans cell histiocytosis (LCH) is a rare clonal myeloid neoplasm with prominent inflammatory features and heterogeneous manifestations in adults, often leading to diagnostic delay. We report a 32-year-old man who presented with a two-year history of recurrent ulcerative intertriginous skin lesions refractory to empirical treatment for presumed inflammatory or infectious dermatoses. Biopsy from the ulcer edge showed atypical histiocytoid cells with characteristic nuclear grooves and numerous eosinophils; immunohistochemistry was positive for CD1a, S-100, and Langerin with a Ki-67 index of ~40%, confirming cutaneous LCH. Baseline\n                    <jats:sup>18<\/jats:sup>\n                    F-FDG PET\/CT (August 2022) demonstrated multisystem disease with extensive cutaneous involvement and imaging-suggestive involvement of multiple extracutaneous sites, including multifocal osseous lesions, the thyroid, gastrointestinal tract, lymph nodes, lung (cystic lesions), and an intramuscular nodule. After six cycles of cytarabine-based induction chemotherapy, follow-up PET\/CT (April 2023) showed near-complete metabolic remission with only residual low-grade uptake in the perineal skin and maxillomandibular\/gingival region. In contrast,\n                    <jats:sup>99m<\/jats:sup>\n                    Tc-MDP whole-body bone scintigraphy with SPECT\/CT performed one year later (July 2024) revealed persistent multifocal tracer uptake, most prominent in the craniofacial skeleton and long bones, with corresponding CT changes suggestive of ongoing remodeling. This case highlights the importance of early biopsy of persistent unexplained ulcerative intertriginous lesions in adults to expedite systemic staging, and demonstrates the complementary roles of serial\n                    <jats:sup>18<\/jats:sup>\n                    F-FDG PET\/CT and bone scintigraphy with SPECT\/CT in longitudinal assessment of osseous disease in adult multisystem LCH.\n                  <\/jats:p>","DOI":"10.3389\/fonc.2026.1784088","type":"journal-article","created":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T05:24:29Z","timestamp":1772169869000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Case Report: A rare adult multisystem Langerhans cell histiocytosis involving the skin, thyroid, jaw-periodontal region, and bone: diagnostic challenges and complementary PET\/CT\u2013SPECT\/CT findings"],"prefix":"10.3389","volume":"16","author":[{"given":"Longchuan","family":"Zhuang","sequence":"first","affiliation":[{"name":"Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences","place":["Yantai, Shandong, China"]},{"name":"Department of Nuclear Medicine, Qingdao Central Hospital, University of Health and Rehabilitation Sciences","place":["Qingdao, Shandong, China"]},{"name":"Yantai Key Laboratory of Nuclear Safety for Marine Ecological Environment","place":["Yantai, Shandong, China"]},{"name":"Shandong Key Laboratory of Coastal Zone Environmental Processes and Ecological Security","place":["Yantai, Shandong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kexu","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Nuclear Medicine, Qingdao Central Hospital, University of Health and Rehabilitation Sciences","place":["Qingdao, Shandong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaokun","family":"Qi","sequence":"additional","affiliation":[{"name":"Department of Nuclear Medicine, Qingdao Central Hospital, University of Health and Rehabilitation Sciences","place":["Qingdao, Shandong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jie","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Nuclear Medicine, Qingdao Central Hospital, University of Health and Rehabilitation Sciences","place":["Qingdao, Shandong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Song","family":"Qin","sequence":"additional","affiliation":[{"name":"Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences","place":["Yantai, Shandong, China"]},{"name":"Shandong Key Laboratory of Coastal Zone Environmental Processes and Ecological Security","place":["Yantai, Shandong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hua","family":"Yu","sequence":"additional","affiliation":[{"name":"Affiliated Qingdao Third People\u2019s Hospital, Qingdao University","place":["Qingdao, Shandong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Minggang","family":"Yuan","sequence":"additional","affiliation":[{"name":"Department of Nuclear Medicine, Qingdao Central Hospital, University of Health and Rehabilitation Sciences","place":["Qingdao, Shandong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,2,27]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.3324\/haematol.2021.279857","article-title":"BRAF V600E-positive cells as molecular markers of bone marrow disease in pediatric Langerhans cell histiocytosis","volume":"107","author":"Kudo","year":"2022","journal-title":"Haematologica"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.3389\/fimmu.2023.1275085","article-title":"Langerhans cell histiocytosis: current advances in molecular pathogenesis","volume":"14","author":"Sconocchia","year":"2023","journal-title":"Front Immunol"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1002\/cncr.35301","article-title":"Langerhans cell histiocytosis: NACHO update on progress, chaos, and opportunity on the path to rational cures","volume":"130","author":"Bielamowicz","year":"2024","journal-title":"Cancer"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1182\/blood.2021014343","article-title":"International expert consensus recommendations for the diagnosis and treatment of Langerhans cell histiocytosis in adults","volume":"139","author":"Goyal","year":"2022","journal-title":"Blood"},{"key":"B5","doi-asserted-by":"publisher","first-page":"S671","DOI":"10.1016\/S2152-2650(25)02130-5","article-title":"MPN-645: diagnostic delay in langerhans cell histiocytosis: A costly setback in treatment initiation\u2014A case report and literature review on multisystem LCH","volume":"25","author":"Govindani","year":"2025","journal-title":"Clin Lymphoma Myeloma Leukemia"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.06.00024004","article-title":"Adult pulmonary Langerhans\u2019 cell histiocytosis","volume":"27","author":"Tazi","year":"2006","journal-title":"Eur Respir J"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1507\/endocrj.EJ21-0341","article-title":"Clinical features and difficulty in diagnosis of Langerhans cell histiocytosis in the hypothalamic-pituitary region","volume":"69","author":"Oda","year":"2022","journal-title":"Endocr J"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1007\/s13244-013-0271-7","article-title":"Skeletal involvement in Langerhans cell histiocytosis","volume":"4","author":"Khung","year":"2013","journal-title":"Insights into imaging"},{"key":"B9","doi-asserted-by":"publisher","first-page":"38","DOI":"10.1016\/0030-4220(80)90030-4","article-title":"Histiocytosis X: a review of 114 cases with oral involvement","volume":"49","author":"Hartman","year":"1980","journal-title":"Oral Surg Oral Med Oral Pathol"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1016\/j.tripleo.2005.06.016","article-title":"Langerhans cell histiocytosis: current insights in a molecular age with emphasis on clinical oral and maxillofacial pathology practice","volume":"100","author":"Hicks","year":"2005","journal-title":"Oral Surg Oral Med Oral Pathol Oral Radiol Endod"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.4103\/0972-3919.78253","article-title":"Tc 99m bone scan and fluorodeoxyglucose positron emission tomography in evaluation of disseminated langerhans cell histiocytosis","volume":"25","author":"Sager","year":"2010","journal-title":"Indian J Nucl Med"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1007\/s00259-016-3415-4","article-title":"The EANM practice guidelines for bone scintigraphy","volume":"43","author":"Van den Wyngaert","year":"2016","journal-title":"Eur J Nucl Med Mol Imaging"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.21037\/qims-21-823","article-title":"Role of 18F-FDG PET\/CT in the diagnosis and management of patients with Langerhans cell histiocytosis","volume":"12","author":"Luo","year":"2022","journal-title":"Quant Imaging Med Surg"}],"container-title":["Frontiers in Oncology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fonc.2026.1784088\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T05:24:30Z","timestamp":1772169870000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fonc.2026.1784088\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2,27]]},"references-count":13,"alternative-id":["10.3389\/fonc.2026.1784088"],"URL":"https:\/\/doi.org\/10.3389\/fonc.2026.1784088","relation":{},"ISSN":["2234-943X"],"issn-type":[{"value":"2234-943X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2,27]]},"article-number":"1784088"}}