{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,8]],"date-time":"2026-05-08T05:10:15Z","timestamp":1778217015501,"version":"3.51.4"},"reference-count":28,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T00:00:00Z","timestamp":1777420800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Annular lichenoid dermatitis of youth (ALDY) is a rare lichenoid dermatosis characterized by distinctive clinical and histopathological features. Its etiopathogenesis remains poorly understood, and previously reported cases have consistently demonstrated polyclonal T-cell receptor (TCR) gene rearrangements. We report a patient with clinical, histopathological, and immunohistochemical findings consistent with ALDY in whom molecular analysis revealed monoclonal T-cell receptor rearrangement within the skin lesions. To our knowledge, this represents the first reported case of ALDY demonstrating T-cell monoclonality. This novel finding expands the current understanding of the molecular spectrum of ALDY and raises the possibility that cases with monoclonal T-cell rearrangement may represent a distinct clinicopathological variant. Based on our findings, we tentatively propose the term monoclonal annular lichenoid dermatitis of youth (MALDY) to describe this potential entity. Further studies are warranted to clarify its clinical significance and relationship to other cutaneous T-cell disorders.<\/jats:p>","DOI":"10.3390\/ijms27093990","type":"journal-article","created":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T08:03:47Z","timestamp":1777536227000},"page":"3990","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Monoclonal Annular Lichenoid Dermatitis of Youth as a New Entity: A Case Report and Review of the Literature"],"prefix":"10.3390","volume":"27","author":[{"given":"Olga","family":"Tockova","sequence":"first","affiliation":[{"name":"Department of Dermatovenereology, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2519-4628","authenticated-orcid":false,"given":"Violeta","family":"Hosta","sequence":"additional","affiliation":[{"name":"Department of Dermatovenereology, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tanja Planinsek","family":"Rucigaj","sequence":"additional","affiliation":[{"name":"Department of Dermatovenereology, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-1700-5115","authenticated-orcid":false,"given":"Svjetlana","family":"Ponorac","sequence":"additional","affiliation":[{"name":"Juventina Clinic, 1000 Ljubljana, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ira","family":"Kokovic","sequence":"additional","affiliation":[{"name":"Department of Molecular Diagnostics, Institute of Oncology Ljubljana, 1000 Ljubljana, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eduardo","family":"Calonje","sequence":"additional","affiliation":[{"name":"St John\u2019s Institute of Dermatology, South Wing, St Thomas\u2019 Hospital, London SE1 7EP, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2534-8671","authenticated-orcid":false,"given":"Bostjan","family":"Luzar","sequence":"additional","affiliation":[{"name":"Institute of Pathology, University of Ljubljana, 1000 Ljubljana, Slovenia"},{"name":"Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1029","DOI":"10.1016\/S0190-9622(03)02147-9","article-title":"Annular lichenoid dermatitis of youth","volume":"49","author":"Annessi","year":"2003","journal-title":"J. Am. Acad. Dermatol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"23","DOI":"10.3390\/dermatopathology9010004","article-title":"Annular lichenoid dermatitis (of youth)","volume":"9","author":"Annessi","year":"2022","journal-title":"Dermatopathology"},{"key":"ref_3","first-page":"72","article-title":"Annular Lichenoid Dermatitis of Youth: Its Pathogenesis, Diagnosis, and Management","volume":"21","author":"Bardawil","year":"2023","journal-title":"Skinmed"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1159\/000546701","article-title":"The Importance of Histopathology in the Diagnosis of Annular Lichenoid Dermatitis of Youth: A Case Report","volume":"17","author":"Bushati","year":"2025","journal-title":"Case Rep. Dermatol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"577","DOI":"10.1111\/j.1525-1470.2008.00762.x","article-title":"A further case of Annular lichenoid dermatitis of Youth: Role of the anti-Hepatitis B immunization","volume":"25","author":"Sans","year":"2008","journal-title":"Pediatr. Dermatol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"653","DOI":"10.1111\/j.1610-0387.2008.06575.x","article-title":"Annular lichenoid dermatitis of youth\u2014A further case in a 12-year-old girl","volume":"6","author":"Kleikamp","year":"2008","journal-title":"J. Dtsch. Dermatol. Ges."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"263","DOI":"10.1097\/DAD.0b013e31819af679","article-title":"Annular lichenoid dermatitis of youth\u2026 and beyond: A series of 6 cases","volume":"31","author":"Cesinaro","year":"2009","journal-title":"Am. J. Dermatopathol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1016\/j.jaad.2012.01.030","article-title":"Annular lichenoid dermatitis of youth in an American boy","volume":"68","author":"Leger","year":"2013","journal-title":"J. Am. Acad. Dermatol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1159\/000381705","article-title":"Annular lichenoid dermatitis of youth: Report of six new cases with review of the literature","volume":"231","author":"Gisondi","year":"2015","journal-title":"Dermatology"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"420","DOI":"10.1111\/cup.12477","article-title":"Annular lichenoid dermatitis of youth: A separate entity or on the spectrum of mycosis fungoides? Case report and review of the literature","volume":"42","author":"Kazlouskaya","year":"2015","journal-title":"J. Cutan. Pathol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"e39","DOI":"10.1016\/j.ad.2015.09.022","article-title":"Annular Lichenoid Dermatitis of Youth: A Report of 2 Cases and a Review of the Literature","volume":"107","year":"2016","journal-title":"Actas Dermosifiliogr."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"e360","DOI":"10.1111\/pde.12987","article-title":"Annular Lichenoid Deramtitis of Youth: A chronic Case Managed Using Pimecrolimus","volume":"33","author":"Malachowski","year":"2016","journal-title":"Pediatr. Dermatol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1097\/DAD.0000000000000621","article-title":"Annular lichenoid dermatitis (of youth). Immunohistochemical and serological evidence for another clinical presentation of Borrelia infection in patients of western Austria","volume":"39","author":"Wilk","year":"2017","journal-title":"Am. J. Dermatopathol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"914","DOI":"10.1097\/DAD.0000000000000903","article-title":"Annular Licenoid Dermatitis (of Youth): Report of case with Lichen Planus-Like Features","volume":"39","author":"Cesinaro","year":"2017","journal-title":"Am. J. Dermatopathol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"365","DOI":"10.1016\/j.annder.2018.02.009","article-title":"Annular lichenoid dermatitis of youth: A case report and literature review","volume":"145","author":"Debois","year":"2018","journal-title":"Ann. Dermatol. Venereol."},{"key":"ref_16","first-page":"e13285","article-title":"Annular lichenoid dermatitis of youth\u2014Recurrent case of rare skin disease treated with cyclosporine","volume":"33","author":"Lekic","year":"2020","journal-title":"Dermatol. Ther."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"e48","DOI":"10.1111\/jdv.19415","article-title":"Dermoscopy of annular lichenoid dermatitis of youth (ALDY): An observational controlled study","volume":"38","author":"Errichetti","year":"2024","journal-title":"J. Eur. Acad. Dermatol. Venereol."},{"key":"ref_18","first-page":"e28","article-title":"Annular lichenoid dermatitis of youth","volume":"100","year":"2024","journal-title":"An. Pediatr."},{"key":"ref_19","unstructured":"Bancroft, J.D., and Gamble, M. (2019). Bancroft\u2019s Theory and Practice of Histological Techniques, Elsevier. [8th ed.]."},{"key":"ref_20","unstructured":"Woods, A.E., and Ellis, R.C. (2019). Laboratory Histopathology: A Complete Reference, Churchill Livingstone Elsevier. [2nd ed.]."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"155","DOI":"10.2478\/raon-2013-0072","article-title":"Clonality analysis of lymphoid proliferations using the BIOMED-2 clonality assays: A single institution experience","volume":"48","author":"Kokovic","year":"2014","journal-title":"Radiol. Oncol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2159","DOI":"10.1038\/leu.2012.246","article-title":"EuroClonality\/BIOMED-2 Guidelines for Interpretation and Reporting of Ig\/TCR Clonality Testing in Suspected Lymphoproliferations","volume":"26","author":"Langerak","year":"2012","journal-title":"Leukemia"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1016\/0190-9622(93)70176-T","article-title":"Lichenoid drug eruptions","volume":"29","author":"Halevy","year":"1993","journal-title":"J. Am. Acad. Dermatol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2257","DOI":"10.1038\/sj.leu.2403202","article-title":"Design and standardization of PCR primers and protocols for detection of clonal immunoglobulin and T-cell receptor gene recombinations in suspect lymphoproliferations: Report of the BIOMED-2 Concerted Action BMH4-CT98-3936","volume":"17","author":"Langerak","year":"2003","journal-title":"Leukemia"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"554","DOI":"10.1016\/S0190-9622(98)70003-9","article-title":"Immunophenotyping and T-cell receptor gamma gene rearrangement analysis as an adjunct to the histopathologic diagnosis of mycosis fungoides","volume":"39","author":"Bergman","year":"1998","journal-title":"J. Am. Acad. Dermatol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"565","DOI":"10.1111\/j.1365-2133.2005.06400.x","article-title":"Lymphomatoid annular erythema: A new form of juvenile mycosis fungoides","volume":"152","author":"Cogrel","year":"2005","journal-title":"Br. J. Dermatol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"914","DOI":"10.1067\/mjd.2002.124696","article-title":"Mycosis fungoides: The great imitator","volume":"47","author":"Zackheim","year":"2002","journal-title":"J. Am. Acad. Dermatol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"696","DOI":"10.1016\/S0190-9622(98)70198-7","article-title":"Mycosis fungoides in young patients: Clinical characteristics and outcome","volume":"38","author":"Crowley","year":"1998","journal-title":"J. Am. Acad. Dermatol."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/9\/3990\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,8]],"date-time":"2026-05-08T04:20:30Z","timestamp":1778214030000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/9\/3990"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,29]]},"references-count":28,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,5]]}},"alternative-id":["ijms27093990"],"URL":"https:\/\/doi.org\/10.3390\/ijms27093990","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,29]]}}}