{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,24]],"date-time":"2026-04-24T13:59:33Z","timestamp":1777039173945,"version":"3.51.4"},"reference-count":22,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T00:00:00Z","timestamp":1770681600000},"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. Immunol."],"abstract":"<jats:p>Neurological and autoimmune muscle comorbidities are rare in thymoma-associated myasthenia gravis (TAMG). The incidence of myositis is likely underestimated due to its clinical similarity. Few cases of autoimmune encephalitis (AE) have been reported in TAMG, most of which are associated with neuronal surface antibodies. We present the case of a 41-year-old woman with weakness and bulbar dysfunction, and elevated muscle and cardiac enzyme levels, who developed seizures and a decreased level of consciousness. Among the complementary tests, electromyography revealed a postsynaptic neuromuscular junction disorder. Muscle biopsy revealed inflammatory myopathy (IM), and cardiac magnetic resonance imaging (MRI) showed myocardial edema. Electroencephalography showed epileptiform activity, while brain MRI revealed bilateral T2\/FLAIR hyperintensities in the medial temporal lobe. Neuroimmunological studies detected anti-acetylcholine receptor and anti-glutamic acid decarboxylase 65 (anti-GAD65) antibodies. Chest computed tomography (CT) revealed a mediastinal mass, which was later confirmed as a thymoma. The patient received corticosteroids, intravenous immunoglobulin, plasma exchanges, and rituximab. The simultaneous coexistence of myasthenia, myositis, myocarditis, and AE in a patient with thymoma has not been previously described in the medical literature. The presence of anti-GAD65 in this context is exceptional. In this case, early recognition and aggressive treatment led to a remarkable recovery. Clinicians should maintain a high index of suspicion for the coexistence of autoimmune disorders in patients with TAMG. IM may indicate a more serious disease, and myocarditis can be life-threatening. Neurological signs, such as memory loss, confusion, and seizures, may indicate the development of AE.<\/jats:p>","DOI":"10.3389\/fimmu.2026.1763320","type":"journal-article","created":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T07:20:05Z","timestamp":1770708005000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Case Report: Thymoma-associated myasthenia gravis, myositis, myocarditis, and anti-GAD65 autoimmune encephalitis: a unique case of paraneoplastic polyautoimmunity"],"prefix":"10.3389","volume":"17","author":[{"given":"Enmanuel A.","family":"Leiva-Murillo","sequence":"first","affiliation":[{"name":"Muscle Research Unit, Department of Internal Medicine, Hospital Cl\u00ednic, University of Barcelona","place":["Barcelona, Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eugenia","family":"Mart\u00ednez-Hern\u00e1ndez","sequence":"additional","affiliation":[{"name":"Department of Neurology, Hospital Cl\u00ednic, University of Barcelona, Neuroimmunology Program, Institut d\u2019Investigacions Biom\u00e8diques August Pi i Sunyer\/CaixaResearch Institute","place":["Barcelona, Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Iban","family":"Aldecoa","sequence":"additional","affiliation":[{"name":"Department of Pathology, Hospital Cl\u00ednic, University of Barcelona, and Neurological Tissue Bank of the Biobank Fundaci\u00f3 Cl\u00ednic per a la Recerca Biom\u00e8dica (FCRB)\/Institut d\u2019Investigacions Biom\u00e8diques August Pi i Sunyer (IDIBAPS), Hospital Cl\u00ednic","place":["Barcelona, Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pedro","family":"Castro","sequence":"additional","affiliation":[{"name":"Medical Intensive Care Unit, Hospital Cl\u00ednic-IDIBAPS, University of Barcelona","place":["Barcelona, Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Valeria","family":"Richart","sequence":"additional","affiliation":[{"name":"Imaging Diagnostic Center, Department of Radiology, Hospital Cl\u00ednic, University of Barcelona","place":["Barcelona, Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jos\u00e9 C.","family":"Milisenda","sequence":"additional","affiliation":[{"name":"Muscle Research Unit, Department of Internal Medicine, Hospital Cl\u00ednic, University of Barcelona","place":["Barcelona, Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ana","family":"Matas-Garc\u00eda","sequence":"additional","affiliation":[{"name":"Muscle Research Unit, Department of Internal Medicine, Hospital Cl\u00ednic, University of Barcelona","place":["Barcelona, Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,2,10]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1016\/j.humimm.2011.12.022","article-title":"High prevalence of infections and autoimmunity in patients with thymoma","volume":"73","author":"Holbro","year":"2012","journal-title":"Hum Immunol"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.3109\/00207454.2010.539307","article-title":"Frequency of autoimmune diseases in myasthenia gravis: a systematic review","volume":"121","author":"Mao","year":"2011","journal-title":"Int J Neurosci"},{"key":"B3","doi-asserted-by":"publisher","first-page":"594","DOI":"10.1111\/joim.12310","article-title":"The autoimmune spectrum of myasthenia gravis: a Swedish population-based study","volume":"277","author":"Fang","year":"2015","journal-title":"J Intern Med"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.3109\/08916934.2015.10306147","article-title":"Complicating autoimmune diseases in myasthenia gravis: a review","volume":"48","author":"Nacu","year":"2015","journal-title":"Autoimmunity"},{"key":"B5","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1038\/s41572-019-0079-y","article-title":"Myasthenia gravis","volume":"5","author":"Gilhus","year":"2019","journal-title":"Nat Rev Dis Primers"},{"key":"B6","doi-asserted-by":"publisher","first-page":"e031454","DOI":"10.1161\/JAHA.123.031454","article-title":"Diagnostic approach for suspected acute myocarditis: considerations for standardization and broadening clinical spectrum","volume":"12","author":"Martens","year":"2023","journal-title":"J Am Heart Assoc"},{"key":"B7","doi-asserted-by":"publisher","first-page":"391","DOI":"10.1016\/S1474-4422(15)00401-9","article-title":"A clinical approach to diagnosis of autoimmune encephalitis","volume":"15","author":"Graus","year":"2016","journal-title":"Lancet Neurol"},{"key":"B8","doi-asserted-by":"publisher","first-page":"45","DOI":"10.1007\/s00281-021-00842-3","article-title":"Thymus and autoimmunity","volume":"43","author":"Marx","year":"2021","journal-title":"Semin Immunopathol"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.3109\/08916930903555935","article-title":"Thymoma and paraneoplastic myasthenia gravis","volume":"43","author":"Marx","year":"2010","journal-title":"Autoimmunity"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1016\/j.autrev.2020.102498","article-title":"Muscle involvement in myasthenia gravis: expanding the clinical spectrum of myasthenia-myositis association from a large cohort of patients","volume":"19","author":"Garibaldi","year":"2020","journal-title":"Autoimmun Rev"},{"key":"B11","doi-asserted-by":"publisher","first-page":"e535","DOI":"10.1212\/NXI.0000000000000535","article-title":"Inflammatory myopathy with myasthenia gravis: thymoma association and polymyositis pathology","volume":"6","author":"Uchio","year":"2019","journal-title":"Neurol Neuroimmunol Neuroinflamm"},{"key":"B12","doi-asserted-by":"publisher","first-page":"1334","DOI":"10.1001\/archneurol.2009.229","article-title":"Autoimmune targets of heart and skeletal muscles in myasthenia gravis","volume":"66","author":"Suzuki","year":"2009","journal-title":"Arch Neurol"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.1111\/ene.12234","article-title":"Cardiac involvements in myasthenia gravis associated with anti-Kv1.4 antibodies","volume":"21","author":"Suzuki","year":"2014","journal-title":"Eur J Neurol"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.3389\/fneur.2022.873599","article-title":"Clinical characteristics and prognosis of anti-AChR positive myasthenia gravis combined with anti-LRP4 or anti-titin antibody","volume":"13","author":"Chen","year":"2022","journal-title":"Front Neurol"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1136\/ard-2022-223792","article-title":"Transcriptomic profiling reveals distinct subsets of immune checkpoint inhibitor induced myositis","volume":"82","author":"Pinal-Fernandez","year":"2023","journal-title":"Ann Rheum Dis"},{"key":"B16","doi-asserted-by":"publisher","first-page":"e2242","DOI":"10.1002\/brb3.2242","article-title":"A systematic review of myasthenia gravis complicated with myocarditis","volume":"11","author":"Cheng","year":"2021","journal-title":"Brain Behav"},{"key":"B17","doi-asserted-by":"publisher","first-page":"e1053","DOI":"10.1212\/NXI.0000000000001053","article-title":"Thymoma and autoimmune encephalitis: clinical manifestations and antibodies","volume":"8","author":"Guasp","year":"2021","journal-title":"Neurol Neuroimmunol Neuroinflamm"},{"key":"B18","doi-asserted-by":"publisher","first-page":"e14568","DOI":"10.1111\/cns.14568","article-title":"Thymoma-associated autoimmune encephalitis with myasthenia gravis: case series and literature review","volume":"30","author":"Su","year":"2024","journal-title":"CNS Neurosci Ther"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.1002\/ana.21917","article-title":"Antibodies to glutamic acid decarboxylase define a form of limbic encephalitis","volume":"67","author":"Malter","year":"2010","journal-title":"Ann Neurol"},{"key":"B20","doi-asserted-by":"publisher","first-page":"874","DOI":"10.1001\/jamaneurol.2015.0749","article-title":"Paraneoplastic neurological syndromes and glutamic acid decarboxylase antibodies","volume":"72","author":"Ari\u00f1o","year":"2015","journal-title":"JAMA Neurol"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1007\/s10072-024-07933-7","article-title":"The limbic and extra-limbic encephalitis associated with glutamic acid decarboxylase (GAD)-65 antibodies: an observational study","volume":"46","author":"Kuang","year":"2025","journal-title":"Neurol Sci"},{"key":"B22","doi-asserted-by":"publisher","DOI":"10.1016\/j.yebeh.2018.01.021","article-title":"Antiglutamic acid decarboxylase 65 (GAD65) antibody-associated epilepsy","volume":"80","author":"Daif","year":"2018","journal-title":"Epilepsy Behav"}],"container-title":["Frontiers in Immunology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2026.1763320\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T07:20:06Z","timestamp":1770708006000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2026.1763320\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2,10]]},"references-count":22,"alternative-id":["10.3389\/fimmu.2026.1763320"],"URL":"https:\/\/doi.org\/10.3389\/fimmu.2026.1763320","relation":{},"ISSN":["1664-3224"],"issn-type":[{"value":"1664-3224","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2,10]]},"article-number":"1763320"}}